53 files changed, 42 insertions, 98 deletions

diff --git a/sphinx/builders/_epub_base.py b/sphinx/builders/_epub_base.py
index f06ff520b..dfe4877ec 100644
--- a/sphinx/builders/_epub_base.py
+++ b/sphinx/builders/_epub_base.py
@@ -603,8 +603,7 @@ class EpubBuilder(StandaloneHTMLBuilder):
                                             html.escape(self.refnodes[0]['refuri'])))
 
         # write the project file
-        content_t = path.join(self.template_dir, 'content.opf.jinja')
-        copy_asset_file(content_t, self.outdir, metadata)
+        copy_asset_file(path.join(self.template_dir, 'content.opf_t'), self.outdir, metadata)
 
     def new_navpoint(self, node: dict[str, Any], level: int, incr: bool = True) -> NavPoint:
         """Create a new entry in the toc from the node at given level."""
@@ -687,7 +686,7 @@ class EpubBuilder(StandaloneHTMLBuilder):
         navpoints = self.build_navpoints(refnodes)
         level = max(item['level'] for item in self.refnodes)
         level = min(level, self.config.epub_tocdepth)
-        copy_asset_file(path.join(self.template_dir, 'toc.ncx.jinja'), self.outdir,
+        copy_asset_file(path.join(self.template_dir, 'toc.ncx_t'), self.outdir,
                         self.toc_metadata(level, navpoints))
 
     def build_epub(self) -> None:
diff --git a/sphinx/builders/changes.py b/sphinx/builders/changes.py
index f6b9152f9..5c118bef9 100644
--- a/sphinx/builders/changes.py
+++ b/sphinx/builders/changes.py
@@ -133,10 +133,10 @@ class ChangesBuilder(Builder):
                 f.write(self.templates.render('changes/rstsource.html', ctx))
         themectx = {'theme_' + key: val for (key, val) in
                     self.theme.get_options({}).items()}
-        default_t = path.join(package_dir, 'themes', 'default', 'static', 'default.css.jinja')
-        copy_asset_file(default_t, self.outdir, context=themectx, renderer=self.templates)
-        basic = path.join(package_dir, 'themes', 'basic', 'static', 'basic.css')
-        copy_asset_file(basic, self.outdir)
+        copy_asset_file(path.join(package_dir, 'themes', 'default', 'static', 'default.css_t'),
+                        self.outdir, context=themectx, renderer=self.templates)
+        copy_asset_file(path.join(package_dir, 'themes', 'basic', 'static', 'basic.css'),
+                        self.outdir)
 
     def hl(self, text: str, version: str) -> str:
         text = html.escape(text)
diff --git a/sphinx/builders/epub3.py b/sphinx/builders/epub3.py
index aaae0bcee..03f4684d1 100644
--- a/sphinx/builders/epub3.py
+++ b/sphinx/builders/epub3.py
@@ -184,7 +184,7 @@ class Epub3Builder(_epub_base.EpubBuilder):
             # 'includehidden'
             refnodes = self.refnodes
         navlist = self.build_navlist(refnodes)
-        copy_asset_file(path.join(self.template_dir, 'nav.xhtml.jinja'), self.outdir,
+        copy_asset_file(path.join(self.template_dir, 'nav.xhtml_t'), self.outdir,
                         self.navigation_doc_metadata(navlist))
 
         # Add nav.xhtml to epub file
diff --git a/sphinx/builders/gettext.py b/sphinx/builders/gettext.py
index 414ed50bd..4d460109b 100644
--- a/sphinx/builders/gettext.py
+++ b/sphinx/builders/gettext.py
@@ -283,7 +283,7 @@ class MessageCatalogBuilder(I18nBuilder):
             ensuredir(path.join(self.outdir, path.dirname(textdomain)))
 
             context['messages'] = list(catalog)
-            content = GettextRenderer(outdir=self.outdir).render('message.pot.jinja', context)
+            content = GettextRenderer(outdir=self.outdir).render('message.pot_t', context)
 
             pofn = path.join(self.outdir, textdomain + '.pot')
             if should_write(pofn, content):
diff --git a/sphinx/builders/latex/__init__.py b/sphinx/builders/latex/__init__.py
index 8efa3ad1c..335518f23 100644
--- a/sphinx/builders/latex/__init__.py
+++ b/sphinx/builders/latex/__init__.py
@@ -402,7 +402,7 @@ class LaTeXBuilder(Builder):
         # use pre-1.6.x Makefile for make latexpdf on Windows
         if os.name == 'nt':
             staticdirname = path.join(package_dir, 'texinputs_win')
-            copy_asset_file(path.join(staticdirname, 'Makefile.jinja'),
+            copy_asset_file(path.join(staticdirname, 'Makefile_t'),
                             self.outdir, context=context)
 
     @progress_message(__('copying additional files'))
@@ -441,7 +441,7 @@ class LaTeXBuilder(Builder):
         if self.context['babel'] or self.context['polyglossia']:
             context['addtocaptions'] = r'\addto\captions%s' % self.babel.get_language()
 
-        filename = path.join(package_dir, 'templates', 'latex', 'sphinxmessages.sty.jinja')
+        filename = path.join(package_dir, 'templates', 'latex', 'sphinxmessages.sty_t')
         copy_asset_file(filename, self.outdir, context=context, renderer=LaTeXRenderer())
 
 
diff --git a/sphinx/cmd/quickstart.py b/sphinx/cmd/quickstart.py
index 580fa7d6d..6122ddd98 100644
--- a/sphinx/cmd/quickstart.py
+++ b/sphinx/cmd/quickstart.py
@@ -370,29 +370,29 @@ def generate(
             if 'quiet' not in d:
                 print(__('File %s already exists, skipping.') % fpath)
 
-    conf_path = os.path.join(templatedir, 'conf.py.jinja') if templatedir else None
+    conf_path = os.path.join(templatedir, 'conf.py_t') if templatedir else None
     if not conf_path or not path.isfile(conf_path):
-        conf_path = os.path.join(package_dir, 'templates', 'quickstart', 'conf.py.jinja')
+        conf_path = os.path.join(package_dir, 'templates', 'quickstart', 'conf.py_t')
     with open(conf_path, encoding="utf-8") as f:
         conf_text = f.read()
 
     write_file(path.join(srcdir, 'conf.py'), template.render_string(conf_text, d))
 
     masterfile = path.join(srcdir, d['master'] + d['suffix'])
-    if template._has_custom_template('quickstart/master_doc.rst.jinja'):
+    if template._has_custom_template('quickstart/master_doc.rst_t'):
         msg = ('A custom template `master_doc.rst_t` found. It has been renamed to '
                '`root_doc.rst_t`.  Please rename it on your project too.')
         print(colorize('red', msg))
-        write_file(masterfile, template.render('quickstart/master_doc.rst.jinja', d))
+        write_file(masterfile, template.render('quickstart/master_doc.rst_t', d))
     else:
-        write_file(masterfile, template.render('quickstart/root_doc.rst.jinja', d))
+        write_file(masterfile, template.render('quickstart/root_doc.rst_t', d))
 
     if d.get('make_mode') is True:
-        makefile_template = 'quickstart/Makefile.new.jinja'
-        batchfile_template = 'quickstart/make.bat.new.jinja'
+        makefile_template = 'quickstart/Makefile.new_t'
+        batchfile_template = 'quickstart/make.bat.new_t'
     else:
-        makefile_template = 'quickstart/Makefile.jinja'
-        batchfile_template = 'quickstart/make.bat.jinja'
+        makefile_template = 'quickstart/Makefile_t'
+        batchfile_template = 'quickstart/make.bat_t'
 
     if d['makefile'] is True:
         d['rsrcdir'] = 'source' if d['sep'] else '.'
diff --git a/sphinx/deprecation.py b/sphinx/deprecation.py
index 7d5a2d2ab..fbd5463cc 100644
--- a/sphinx/deprecation.py
+++ b/sphinx/deprecation.py
@@ -62,31 +62,3 @@ def _deprecation_warning(
 
     warnings.warn(message + " Check CHANGES for Sphinx API modifications.",
                   warning_class, stacklevel=3)
-
-
-class OldJinjaSuffixWarning(PendingDeprecationWarning):
-    """Warning class for ``_old_jinja_template_suffix_warning``.
-
-    This class exists only so that extensions and themes can silence the legacy
-    filename warning via Python's `warning control`_ mechanisms. See
-    :ref:`theming-static-templates` for an example.
-
-    This warning class will be removed, and the warning class changed to the
-    appropriate RemovedInSphinx_0Warning no earlier than 31 December 2024, at
-    which point the standard deprecation process for ``_t`` template suffixes
-    will start.
-
-    .. _warning control: https://docs.python.org/3/library/warnings.html#the-warnings-filter
-    """
-
-
-def _old_jinja_template_suffix_warning(filename: str) -> None:
-    if filename.endswith('_t'):
-        warnings.warn(
-            f"{filename!r}: the '_t' suffix for Jinja templates is deprecated. "
-            "If the file is a template, use the suffix '.jinja' instead. "
-            'For more information, see '
-            'https://www.sphinx-doc.org/en/master/development/theming.html#static-templates',
-            OldJinjaSuffixWarning,
-            stacklevel=3,
-        )
diff --git a/sphinx/ext/apidoc.py b/sphinx/ext/apidoc.py
index 9c9336075..108515d73 100644
--- a/sphinx/ext/apidoc.py
+++ b/sphinx/ext/apidoc.py
@@ -102,7 +102,7 @@ def create_module_file(package: str, basename: str, opts: Any,
         'qualname': qualname,
         'automodule_options': options,
     }
-    text = ReSTRenderer([user_template_dir, template_dir]).render('module.rst.jinja', context)
+    text = ReSTRenderer([user_template_dir, template_dir]).render('module.rst_t', context)
     write_file(qualname, text, opts)
 
 
@@ -138,8 +138,7 @@ def create_package_file(root: str, master_package: str, subroot: str, py_files:
         'show_headings': not opts.noheadings,
         'maxdepth': opts.maxdepth,
     }
-    engine = ReSTRenderer([user_template_dir, template_dir])
-    text = engine.render('package.rst.jinja', context)
+    text = ReSTRenderer([user_template_dir, template_dir]).render('package.rst_t', context)
     write_file(pkgname, text, opts)
 
     if submodules and opts.separatemodules:
@@ -164,7 +163,7 @@ def create_modules_toc_file(modules: list[str], opts: Any, name: str = 'modules'
         'maxdepth': opts.maxdepth,
         'docnames': modules,
     }
-    text = ReSTRenderer([user_template_dir, template_dir]).render('toc.rst.jinja', context)
+    text = ReSTRenderer([user_template_dir, template_dir]).render('toc.rst_t', context)
     write_file(name, text, opts)
 
 
diff --git a/sphinx/ext/imgmath.py b/sphinx/ext/imgmath.py
index 975cbcca5..34d716686 100644
--- a/sphinx/ext/imgmath.py
+++ b/sphinx/ext/imgmath.py
@@ -19,7 +19,6 @@ from sphinx import package_dir
 from sphinx.application import Sphinx
 from sphinx.builders import Builder
 from sphinx.config import Config
-from sphinx.deprecation import _old_jinja_template_suffix_warning
 from sphinx.errors import SphinxError
 from sphinx.locale import _, __
 from sphinx.util import logging, sha1
@@ -96,20 +95,16 @@ def generate_latex_macro(image_format: str,
     }
 
     if config.imgmath_use_preview:
-        template_name = 'preview.tex'
+        template_name = 'preview.tex_t'
     else:
-        template_name = 'template.tex'
+        template_name = 'template.tex_t'
 
     for template_dir in config.templates_path:
-        # TODO: deprecate '_t' template suffix support after 2024-12-31
-        for template_suffix in ('_t', '.jinja'):
-            template = path.join(confdir, template_dir, template_name + template_suffix)
-            if path.exists(template):
-                _old_jinja_template_suffix_warning(template)
-                return LaTeXRenderer().render(template, variables)
-
-    # Default: fallback to a pathless in-library jinja template
-    return LaTeXRenderer(templates_path).render(f"{template_name}.jinja", variables)
+        template = path.join(confdir, template_dir, template_name)
+        if path.exists(template):
+            return LaTeXRenderer().render(template, variables)
+
+    return LaTeXRenderer(templates_path).render(template_name, variables)
 
 
 def ensure_tempdir(builder: Builder) -> str:
diff --git a/sphinx/templates/apidoc/module.rst.jinja b/sphinx/templates/apidoc/module.rst_t
index 249027855..249027855 100644
--- a/sphinx/templates/apidoc/module.rst.jinja
+++ b/sphinx/templates/apidoc/module.rst_t
diff --git a/sphinx/templates/apidoc/package.rst.jinja b/sphinx/templates/apidoc/package.rst_t
index 2229c311b..2229c311b 100644
--- a/sphinx/templates/apidoc/package.rst.jinja
+++ b/sphinx/templates/apidoc/package.rst_t
diff --git a/sphinx/templates/apidoc/toc.rst.jinja b/sphinx/templates/apidoc/toc.rst_t
index f0877eeb2..f0877eeb2 100644
--- a/sphinx/templates/apidoc/toc.rst.jinja
+++ b/sphinx/templates/apidoc/toc.rst_t
diff --git a/sphinx/templates/epub3/content.opf.jinja b/sphinx/templates/epub3/content.opf_t
index 417888c7e..417888c7e 100644
--- a/sphinx/templates/epub3/content.opf.jinja
+++ b/sphinx/templates/epub3/content.opf_t
diff --git a/sphinx/templates/epub3/nav.xhtml.jinja b/sphinx/templates/epub3/nav.xhtml_t
index 2a32c2039..2a32c2039 100644
--- a/sphinx/templates/epub3/nav.xhtml.jinja
+++ b/sphinx/templates/epub3/nav.xhtml_t
diff --git a/sphinx/templates/epub3/toc.ncx.jinja b/sphinx/templates/epub3/toc.ncx_t
index 0ea7ca366..0ea7ca366 100644
--- a/sphinx/templates/epub3/toc.ncx.jinja
+++ b/sphinx/templates/epub3/toc.ncx_t
diff --git a/sphinx/templates/gettext/message.pot.jinja b/sphinx/templates/gettext/message.pot_t
index 6138f54c9..6138f54c9 100644
--- a/sphinx/templates/gettext/message.pot.jinja
+++ b/sphinx/templates/gettext/message.pot_t
diff --git a/sphinx/templates/imgmath/preview.tex.jinja b/sphinx/templates/imgmath/preview.tex_t
index f3fdcda07..f3fdcda07 100644
--- a/sphinx/templates/imgmath/preview.tex.jinja
+++ b/sphinx/templates/imgmath/preview.tex_t
diff --git a/sphinx/templates/imgmath/template.tex.jinja b/sphinx/templates/imgmath/template.tex_t
index 92fa8b021..92fa8b021 100644
--- a/sphinx/templates/imgmath/template.tex.jinja
+++ b/sphinx/templates/imgmath/template.tex_t
diff --git a/sphinx/templates/latex/latex.tex.jinja b/sphinx/templates/latex/latex.tex_t
index deb030504..deb030504 100644
--- a/sphinx/templates/latex/latex.tex.jinja
+++ b/sphinx/templates/latex/latex.tex_t
diff --git a/sphinx/templates/latex/longtable.tex.jinja b/sphinx/templates/latex/longtable.tex_t
index 83790f4b2..83790f4b2 100644
--- a/sphinx/templates/latex/longtable.tex.jinja
+++ b/sphinx/templates/latex/longtable.tex_t
diff --git a/sphinx/templates/latex/sphinxmessages.sty.jinja b/sphinx/templates/latex/sphinxmessages.sty_t
index ef2750f6a..ef2750f6a 100644
--- a/sphinx/templates/latex/sphinxmessages.sty.jinja
+++ b/sphinx/templates/latex/sphinxmessages.sty_t
diff --git a/sphinx/templates/latex/tabular.tex.jinja b/sphinx/templates/latex/tabular.tex_t
index 0a9310a5e..0a9310a5e 100644
--- a/sphinx/templates/latex/tabular.tex.jinja
+++ b/sphinx/templates/latex/tabular.tex_t
diff --git a/sphinx/templates/latex/tabulary.tex.jinja b/sphinx/templates/latex/tabulary.tex_t
index 6ebcec6d2..6ebcec6d2 100644
--- a/sphinx/templates/latex/tabulary.tex.jinja
+++ b/sphinx/templates/latex/tabulary.tex_t
diff --git a/sphinx/templates/quickstart/Makefile.new.jinja b/sphinx/templates/quickstart/Makefile.new_t
index 1a527578b..1a527578b 100644
--- a/sphinx/templates/quickstart/Makefile.new.jinja
+++ b/sphinx/templates/quickstart/Makefile.new_t
diff --git a/sphinx/templates/quickstart/Makefile.jinja b/sphinx/templates/quickstart/Makefile_t
index 14b2dc594..14b2dc594 100644
--- a/sphinx/templates/quickstart/Makefile.jinja
+++ b/sphinx/templates/quickstart/Makefile_t
diff --git a/sphinx/templates/quickstart/conf.py.jinja b/sphinx/templates/quickstart/conf.py_t
index 383648675..383648675 100644
--- a/sphinx/templates/quickstart/conf.py.jinja
+++ b/sphinx/templates/quickstart/conf.py_t
diff --git a/sphinx/templates/quickstart/make.bat.new.jinja b/sphinx/templates/quickstart/make.bat.new_t
index c89237ba2..c89237ba2 100644
--- a/sphinx/templates/quickstart/make.bat.new.jinja
+++ b/sphinx/templates/quickstart/make.bat.new_t
diff --git a/sphinx/templates/quickstart/make.bat.jinja b/sphinx/templates/quickstart/make.bat_t
index dfc619ae3..dfc619ae3 100644
--- a/sphinx/templates/quickstart/make.bat.jinja
+++ b/sphinx/templates/quickstart/make.bat_t
diff --git a/sphinx/templates/quickstart/root_doc.rst.jinja b/sphinx/templates/quickstart/root_doc.rst_t
index 3aa98af08..3aa98af08 100644
--- a/sphinx/templates/quickstart/root_doc.rst.jinja
+++ b/sphinx/templates/quickstart/root_doc.rst_t
diff --git a/sphinx/texinputs/Makefile.jinja b/sphinx/texinputs/Makefile_t
index 96bb0fed1..96bb0fed1 100644
--- a/sphinx/texinputs/Makefile.jinja
+++ b/sphinx/texinputs/Makefile_t
diff --git a/sphinx/texinputs/latexmkjarc.jinja b/sphinx/texinputs/latexmkjarc_t
index c7403a90b..c7403a90b 100644
--- a/sphinx/texinputs/latexmkjarc.jinja
+++ b/sphinx/texinputs/latexmkjarc_t
diff --git a/sphinx/texinputs/latexmkrc.jinja b/sphinx/texinputs/latexmkrc_t
index a33b54148..a33b54148 100644
--- a/sphinx/texinputs/latexmkrc.jinja
+++ b/sphinx/texinputs/latexmkrc_t
diff --git a/sphinx/texinputs/make.bat.jinja b/sphinx/texinputs/make.bat_t
index da2805afd..da2805afd 100644
--- a/sphinx/texinputs/make.bat.jinja
+++ b/sphinx/texinputs/make.bat_t
diff --git a/sphinx/texinputs_win/Makefile.jinja b/sphinx/texinputs_win/Makefile_t
index 4131762a8..4131762a8 100644
--- a/sphinx/texinputs_win/Makefile.jinja
+++ b/sphinx/texinputs_win/Makefile_t
diff --git a/sphinx/themes/agogo/static/agogo.css.jinja b/sphinx/themes/agogo/static/agogo.css_t
index a23869425..a23869425 100644
--- a/sphinx/themes/agogo/static/agogo.css.jinja
+++ b/sphinx/themes/agogo/static/agogo.css_t
diff --git a/sphinx/themes/basic/static/basic.css.jinja b/sphinx/themes/basic/static/basic.css_t
index 9d5e4419d..9d5e4419d 100644
--- a/sphinx/themes/basic/static/basic.css.jinja
+++ b/sphinx/themes/basic/static/basic.css_t
diff --git a/sphinx/themes/basic/static/documentation_options.js.jinja b/sphinx/themes/basic/static/documentation_options.js_t
index fd6943fb3..fd6943fb3 100644
--- a/sphinx/themes/basic/static/documentation_options.js.jinja
+++ b/sphinx/themes/basic/static/documentation_options.js_t
diff --git a/sphinx/themes/basic/static/language_data.js.jinja b/sphinx/themes/basic/static/language_data.js_t
index 80f2a4f53..80f2a4f53 100644
--- a/sphinx/themes/basic/static/language_data.js.jinja
+++ b/sphinx/themes/basic/static/language_data.js_t
diff --git a/sphinx/themes/bizstyle/static/bizstyle.css.jinja b/sphinx/themes/bizstyle/static/bizstyle.css_t
index 1f012c4c2..1f012c4c2 100644
--- a/sphinx/themes/bizstyle/static/bizstyle.css.jinja
+++ b/sphinx/themes/bizstyle/static/bizstyle.css_t
diff --git a/sphinx/themes/bizstyle/static/bizstyle.js.jinja b/sphinx/themes/bizstyle/static/bizstyle.js_t
index fd0865e5d..fd0865e5d 100644
--- a/sphinx/themes/bizstyle/static/bizstyle.js.jinja
+++ b/sphinx/themes/bizstyle/static/bizstyle.js_t
diff --git a/sphinx/themes/classic/static/classic.css.jinja b/sphinx/themes/classic/static/classic.css_t
index 8a903e822..8a903e822 100644
--- a/sphinx/themes/classic/static/classic.css.jinja
+++ b/sphinx/themes/classic/static/classic.css_t
diff --git a/sphinx/themes/classic/static/sidebar.js.jinja b/sphinx/themes/classic/static/sidebar.js_t
index 32ae506aa..32ae506aa 100644
--- a/sphinx/themes/classic/static/sidebar.js.jinja
+++ b/sphinx/themes/classic/static/sidebar.js_t
diff --git a/sphinx/themes/epub/static/epub.css.jinja b/sphinx/themes/epub/static/epub.css_t
index 767d558be..767d558be 100644
--- a/sphinx/themes/epub/static/epub.css.jinja
+++ b/sphinx/themes/epub/static/epub.css_t
diff --git a/sphinx/themes/haiku/static/haiku.css.jinja b/sphinx/themes/haiku/static/haiku.css_t
index bccc3ea06..bccc3ea06 100644
--- a/sphinx/themes/haiku/static/haiku.css.jinja
+++ b/sphinx/themes/haiku/static/haiku.css_t
diff --git a/sphinx/themes/nature/static/nature.css.jinja b/sphinx/themes/nature/static/nature.css_t
index a2f3710e1..a2f3710e1 100644
--- a/sphinx/themes/nature/static/nature.css.jinja
+++ b/sphinx/themes/nature/static/nature.css_t
diff --git a/sphinx/themes/nonav/static/nonav.css.jinja b/sphinx/themes/nonav/static/nonav.css_t
index 71e3ffc08..71e3ffc08 100644
--- a/sphinx/themes/nonav/static/nonav.css.jinja
+++ b/sphinx/themes/nonav/static/nonav.css_t
diff --git a/sphinx/themes/pyramid/static/epub.css.jinja b/sphinx/themes/pyramid/static/epub.css_t
index 798054bdf..798054bdf 100644
--- a/sphinx/themes/pyramid/static/epub.css.jinja
+++ b/sphinx/themes/pyramid/static/epub.css_t
diff --git a/sphinx/themes/pyramid/static/pyramid.css.jinja b/sphinx/themes/pyramid/static/pyramid.css_t
index 4de532798..4de532798 100644
--- a/sphinx/themes/pyramid/static/pyramid.css.jinja
+++ b/sphinx/themes/pyramid/static/pyramid.css_t
diff --git a/sphinx/themes/scrolls/static/scrolls.css.jinja b/sphinx/themes/scrolls/static/scrolls.css_t
index c8b947d40..c8b947d40 100644
--- a/sphinx/themes/scrolls/static/scrolls.css.jinja
+++ b/sphinx/themes/scrolls/static/scrolls.css_t
diff --git a/sphinx/themes/sphinxdoc/static/sphinxdoc.css.jinja b/sphinx/themes/sphinxdoc/static/sphinxdoc.css_t
index 36d05907e..36d05907e 100644
--- a/sphinx/themes/sphinxdoc/static/sphinxdoc.css.jinja
+++ b/sphinx/themes/sphinxdoc/static/sphinxdoc.css_t
diff --git a/sphinx/themes/traditional/static/traditional.css.jinja b/sphinx/themes/traditional/static/traditional.css_t
index 085c98a8c..085c98a8c 100644
--- a/sphinx/themes/traditional/static/traditional.css.jinja
+++ b/sphinx/themes/traditional/static/traditional.css_t
diff --git a/sphinx/util/fileutil.py b/sphinx/util/fileutil.py
index 4185fb246..03928710e 100644
--- a/sphinx/util/fileutil.py
+++ b/sphinx/util/fileutil.py
@@ -8,7 +8,6 @@ from typing import TYPE_CHECKING, Callable
 
 from docutils.utils import relative_path
 
-from sphinx.deprecation import _old_jinja_template_suffix_warning
 from sphinx.util.osutil import copyfile, ensuredir
 from sphinx.util.typing import PathMatcher
 
@@ -16,19 +15,6 @@ if TYPE_CHECKING:
     from sphinx.util.template import BaseRenderer
 
 
-def _template_basename(filename: str) -> str | None:
-    """Given an input filename:
-    If the input looks like a template, then return the filename output should
-    be written to.  Otherwise, return no result (None)."""
-    # TODO: deprecate '_t' template suffix support after 2024-12-31
-    if filename.lower().endswith('_t'):
-        _old_jinja_template_suffix_warning(filename)
-        return filename[:-2]
-    elif filename.lower().endswith(".jinja"):
-        return filename[:-6]
-    return None
-
-
 def copy_asset_file(source: str, destination: str,
                     context: dict | None = None,
                     renderer: BaseRenderer | None = None) -> None:
@@ -49,13 +35,14 @@ def copy_asset_file(source: str, destination: str,
         # Use source filename if destination points a directory
         destination = os.path.join(destination, os.path.basename(source))
 
-    if _template_basename(source) and context is not None:
+    if source.lower().endswith('_t') and context is not None:
         if renderer is None:
             from sphinx.util.template import SphinxRenderer
             renderer = SphinxRenderer()
 
         with open(source, encoding='utf-8') as fsrc:
-            destination = _template_basename(destination) or destination
+            if destination.lower().endswith('_t'):
+                destination = destination[:-2]
             with open(destination, 'w', encoding='utf-8') as fdst:
                 fdst.write(renderer.render_string(fsrc.read(), context))
     else:
diff --git a/sphinx/writers/latex.py b/sphinx/writers/latex.py
index efb847353..5116c2181 100644
--- a/sphinx/writers/latex.py
+++ b/sphinx/writers/latex.py
@@ -16,7 +16,7 @@ from docutils import nodes, writers
 from docutils.nodes import Element, Node, Text
 
 from sphinx import addnodes, highlighting
-from sphinx.deprecation import RemovedInSphinx70Warning, _old_jinja_template_suffix_warning
+from sphinx.deprecation import RemovedInSphinx70Warning
 from sphinx.domains import IndexEntry
 from sphinx.domains.std import StandardDomain
 from sphinx.errors import SphinxError
@@ -435,8 +435,7 @@ class LaTeXTranslator(SphinxTranslator):
             'body': ''.join(self.body),
             'indices': self.generate_indices(),
         })
-        template = self._find_template('latex.tex')
-        return self.render(template, self.elements)
+        return self.render('latex.tex_t', self.elements)
 
     def hypertarget(self, id: str, withdoc: bool = True, anchor: bool = True) -> str:
         if withdoc:
@@ -513,21 +512,14 @@ class LaTeXTranslator(SphinxTranslator):
 
         return ''.join(ret)
 
-    def _find_template(self, template_name: str) -> str:
-        for template_dir in self.config.templates_path:
-            # TODO: deprecate '_t' template suffix support after 2024-12-31
-            for template_suffix in ('_t', '.jinja'):
-                template = path.join(self.builder.confdir, template_dir,
-                                     template_name + template_suffix)
-                if path.exists(template):
-                    _old_jinja_template_suffix_warning(template)
-                    return template
-
-        # Default: fallback to a pathless in-library jinja template
-        return f"{template_name}.jinja"
-
     def render(self, template_name: str, variables: dict[str, Any]) -> str:
         renderer = LaTeXRenderer(latex_engine=self.config.latex_engine)
+        for template_dir in self.config.templates_path:
+            template = path.join(self.builder.confdir, template_dir,
+                                 template_name)
+            if path.exists(template):
+                return renderer.render(template, variables)
+
         return renderer.render(template_name, variables)
 
     @property
@@ -910,8 +902,8 @@ class LaTeXTranslator(SphinxTranslator):
     def depart_table(self, node: Element) -> None:
         labels = self.hypertarget_to(node)
         table_type = self.table.get_table_type()
-        template = self._find_template(f"{table_type}.tex")
-        table = self.render(template, {'table': self.table, 'labels': labels})
+        table = self.render(table_type + '.tex_t',
+                            {'table': self.table, 'labels': labels})
         self.body.append(BLANKLINE)
         self.body.append(table)
         self.body.append(CR)