diff --git a/sphinx/builders/html/__init__.py b/sphinx/builders/html/__init__.py
index 11d5a58b4..3f4ea569f 100644
--- a/sphinx/builders/html/__init__.py
+++ b/sphinx/builders/html/__init__.py
@@ -5,6 +5,7 @@ import os
 import posixpath
 import re
 import sys
+import warnings
 from datetime import datetime
 from os import path
 from typing import IO, Any, Dict, Iterable, Iterator, List, Optional, Set, Tuple, Type
@@ -443,10 +444,14 @@ class StandaloneHTMLBuilder(Builder):
             self.load_indexer(docnames)
 
         self.docwriter = HTMLWriter(self)
-        self.docsettings: Any = OptionParser(
-            defaults=self.env.settings,
-            components=(self.docwriter,),
-            read_config_files=True).get_default_values()
+        with warnings.catch_warnings():
+            warnings.filterwarnings('ignore', category=DeprecationWarning)
+            # DeprecationWarning: The frontend.OptionParser class will be replaced
+            # by a subclass of argparse.ArgumentParser in Docutils 0.21 or later.
+            self.docsettings: Any = OptionParser(
+                defaults=self.env.settings,
+                components=(self.docwriter,),
+                read_config_files=True).get_default_values()
         self.docsettings.compact_lists = bool(self.config.html_compact_lists)
 
         # determine the additional indices to include
diff --git a/sphinx/builders/latex/__init__.py b/sphinx/builders/latex/__init__.py
index d4fc66177..f1611ca80 100644
--- a/sphinx/builders/latex/__init__.py
+++ b/sphinx/builders/latex/__init__.py
@@ -1,6 +1,7 @@
 """LaTeX builder."""
 
 import os
+import warnings
 from os import path
 from typing import Any, Dict, Iterable, List, Tuple, Union
 
@@ -250,10 +251,14 @@ class LaTeXBuilder(Builder):
 
     def write(self, *ignored: Any) -> None:
         docwriter = LaTeXWriter(self)
-        docsettings: Any = OptionParser(
-            defaults=self.env.settings,
-            components=(docwriter,),
-            read_config_files=True).get_default_values()
+        with warnings.catch_warnings():
+            warnings.filterwarnings('ignore', category=DeprecationWarning)
+            # DeprecationWarning: The frontend.OptionParser class will be replaced
+            # by a subclass of argparse.ArgumentParser in Docutils 0.21 or later.
+            docsettings: Any = OptionParser(
+                defaults=self.env.settings,
+                components=(docwriter,),
+                read_config_files=True).get_default_values()
 
         self.init_document_data()
         self.write_stylesheet()
diff --git a/sphinx/builders/manpage.py b/sphinx/builders/manpage.py
index cc6fc1fbe..ad1138c2c 100644
--- a/sphinx/builders/manpage.py
+++ b/sphinx/builders/manpage.py
@@ -1,5 +1,6 @@
 """Manual pages builder."""
 
+import warnings
 from os import path
 from typing import Any, Dict, List, Set, Tuple, Union
 
@@ -45,10 +46,14 @@ class ManualPageBuilder(Builder):
     @progress_message(__('writing'))
     def write(self, *ignored: Any) -> None:
         docwriter = ManualPageWriter(self)
-        docsettings: Any = OptionParser(
-            defaults=self.env.settings,
-            components=(docwriter,),
-            read_config_files=True).get_default_values()
+        with warnings.catch_warnings():
+            warnings.filterwarnings('ignore', category=DeprecationWarning)
+            # DeprecationWarning: The frontend.OptionParser class will be replaced
+            # by a subclass of argparse.ArgumentParser in Docutils 0.21 or later.
+            docsettings: Any = OptionParser(
+                defaults=self.env.settings,
+                components=(docwriter,),
+                read_config_files=True).get_default_values()
 
         for info in self.config.man_pages:
             docname, name, description, authors, section = info
diff --git a/sphinx/builders/texinfo.py b/sphinx/builders/texinfo.py
index 24a19b0df..d506d2121 100644
--- a/sphinx/builders/texinfo.py
+++ b/sphinx/builders/texinfo.py
@@ -1,6 +1,7 @@
 """Texinfo builder."""
 
 import os
+import warnings
 from os import path
 from typing import Any, Dict, Iterable, List, Tuple, Union
 
@@ -101,10 +102,14 @@ class TexinfoBuilder(Builder):
             with progress_message(__("writing")):
                 self.post_process_images(doctree)
                 docwriter = TexinfoWriter(self)
-                settings: Any = OptionParser(
-                    defaults=self.env.settings,
-                    components=(docwriter,),
-                    read_config_files=True).get_default_values()
+                with warnings.catch_warnings():
+                    warnings.filterwarnings('ignore', category=DeprecationWarning)
+                    # DeprecationWarning: The frontend.OptionParser class will be replaced
+                    # by a subclass of argparse.ArgumentParser in Docutils 0.21 or later.
+                    settings: Any = OptionParser(
+                        defaults=self.env.settings,
+                        components=(docwriter,),
+                        read_config_files=True).get_default_values()
                 settings.author = author
                 settings.title = title
                 settings.texinfo_filename = targetname[:-5] + '.info'
diff --git a/tests/test_markup.py b/tests/test_markup.py
index 8800f5499..a97239846 100644
--- a/tests/test_markup.py
+++ b/tests/test_markup.py
@@ -1,6 +1,7 @@
 """Test various Sphinx-specific markup extensions."""
 
 import re
+import warnings
 
 import pytest
 from docutils import frontend, nodes, utils
@@ -22,9 +23,13 @@ from sphinx.writers.latex import LaTeXTranslator, LaTeXWriter
 @pytest.fixture
 def settings(app):
     texescape.init()  # otherwise done by the latex builder
-    optparser = frontend.OptionParser(
-        components=(RstParser, HTMLWriter, LaTeXWriter),
-        defaults=default_settings)
+    with warnings.catch_warnings():
+        warnings.filterwarnings('ignore', category=DeprecationWarning)
+        # DeprecationWarning: The frontend.OptionParser class will be replaced
+        # by a subclass of argparse.ArgumentParser in Docutils 0.21 or later.
+        optparser = frontend.OptionParser(
+            components=(RstParser, HTMLWriter, LaTeXWriter),
+            defaults=default_settings)
     settings = optparser.get_default_values()
     settings.smart_quotes = True
     settings.env = app.builder.env
diff --git a/tests/test_search.py b/tests/test_search.py
index 024e6941c..88c77c75e 100644
--- a/tests/test_search.py
+++ b/tests/test_search.py
@@ -1,5 +1,6 @@
 """Test the search index builder."""
 
+import warnings
 from collections import namedtuple
 from io import BytesIO
 
@@ -27,7 +28,11 @@ settings = parser = None
 
 def setup_module():
     global settings, parser
-    optparser = frontend.OptionParser(components=(rst.Parser,))
+    with warnings.catch_warnings():
+        warnings.filterwarnings('ignore', category=DeprecationWarning)
+        # DeprecationWarning: The frontend.OptionParser class will be replaced
+        # by a subclass of argparse.ArgumentParser in Docutils 0.21 or later.
+        optparser = frontend.OptionParser(components=(rst.Parser,))
     settings = optparser.get_default_values()
     parser = rst.Parser()
 
diff --git a/tests/test_util_nodes.py b/tests/test_util_nodes.py
index 031569d4c..14dcdcd58 100644
--- a/tests/test_util_nodes.py
+++ b/tests/test_util_nodes.py
@@ -1,4 +1,5 @@
 """Tests uti.nodes functions."""
+import warnings
 from textwrap import dedent
 from typing import Any
 
@@ -17,8 +18,12 @@ def _transform(doctree):
 
 
 def create_new_document():
-    settings = frontend.OptionParser(
-        components=(rst.Parser,)).get_default_values()
+    with warnings.catch_warnings():
+        warnings.filterwarnings('ignore', category=DeprecationWarning)
+        # DeprecationWarning: The frontend.OptionParser class will be replaced
+        # by a subclass of argparse.ArgumentParser in Docutils 0.21 or later.
+        settings = frontend.OptionParser(
+            components=(rst.Parser,)).get_default_values()
     settings.id_prefix = 'id'
     document = new_document('dummy.txt', settings)
     return document