diff --git a/MAINTAINERS.yml b/MAINTAINERS.yml
index fd70600643e..6546e62e631 100644
--- a/MAINTAINERS.yml
+++ b/MAINTAINERS.yml
@@ -968,7 +968,6 @@ Documentation:
     - doc/index-tex.rst
     - doc/index.rst
     - doc/kconfig.rst
-    - doc/known-warnings.txt
     - doc/templates/sample.tmpl
     - doc/templates/board.tmpl
     - boards/index.rst
diff --git a/doc/_extensions/zephyr/warnings_filter.py b/doc/_extensions/zephyr/warnings_filter.py
deleted file mode 100644
index 9239776ff79..00000000000
--- a/doc/_extensions/zephyr/warnings_filter.py
+++ /dev/null
@@ -1,133 +0,0 @@
-"""
-Warnings filter extension
-#########################
-
-Copyright (c) 2021 Nordic Semiconductor ASA
-SPDX-License-Identifier: Apache-2.0
-
-Introduction
-============
-
-This Sphinx plugin can be used to filter out warnings that are known to be false
-positives. The warnings are filtered out based on a set of regular expressions
-given via an configuration file. The format of the configuration file is a
-plain-text file where each line consists of a regular expression. Any lines
-starting with ``#`` will be ignored.
-
-Configuration options
-=====================
-
-- ``warnings_filter_config``: Configuration file.
-- ``warnings_filter_silent``: Silent flag. If True, warning is hidden. If False
-  the warning is converted to an information message and displayed.
-"""
-
-import logging
-import re
-from typing import Dict, Any, List, Optional
-
-from sphinx.application import Sphinx
-from sphinx.util.logging import NAMESPACE
-
-
-__version__ = "0.1.0"
-
-
-class WarningsFilter(logging.Filter):
-    """Warnings filter.
-
-    Args:
-        expressions: List of regular expressions.
-        silent: If true, warning is hidden, otherwise it is shown as INFO.
-        name: Filter name.
-    """
-
-    def __init__(self, expressions: List[str], silent: bool, name: str = "") -> None:
-        super().__init__(name)
-
-        self._expressions = expressions
-        self._silent = silent
-
-    def filter(self, record: logging.LogRecord) -> bool:
-        if record.levelno != logging.WARNING:
-            return True
-
-        for expression in self._expressions:
-            # The message isn't always a string so we convert it before regexing as we can only regex strings
-            if expression.match(str(record.msg)):
-                if self._silent:
-                    return False
-                else:
-                    record.levelno = logging.INFO
-                    record.msg = f"Filtered warning: {record.msg}"
-                    return True
-
-        return True
-
-
-class Expression:
-    """
-    Encapsulate a log filter pattern and track if it ever matches a log line.
-    """
-
-    def __init__(self, pattern):
-        self.pattern = pattern
-        self.matched = False
-
-    def match(self, str):
-        matches = bool(re.match(self.pattern, str))
-        self.matched = matches or self.matched
-        return matches
-
-
-def configure(app: Sphinx) -> None:
-    """Entry point.
-
-    Args:
-        app: Sphinx application instance.
-    """
-
-    # load expressions from configuration file
-    with open(app.config.warnings_filter_config) as f:
-        expressions = list()
-        for line in f.readlines():
-            if line.strip() and not line.startswith("#"):
-                expressions.append(Expression(line.rstrip()))
-
-    app.env.warnings_filter_expressions = expressions
-
-    # install warnings filter to all the Sphinx logger handlers
-    filter = WarningsFilter(expressions, app.config.warnings_filter_silent)
-    logger = logging.getLogger(NAMESPACE)
-    for handler in logger.handlers:
-        handler.filters.insert(0, filter)
-
-
-def finished(app: Sphinx, exception: Optional[Exception]):
-    """
-    Prints out any patterns that have not matched a log line to allow us to clean up any that are not used.
-    """
-    if exception:
-        # Early exit if there has been an exception as matching data is only
-        # valid for complete builds
-        return
-
-    expressions = app.env.warnings_filter_expressions
-
-    for expression in expressions:
-        if not expression.matched:
-            logging.warning(f"Unused expression: {expression.pattern}")
-
-
-def setup(app: Sphinx) -> Dict[str, Any]:
-    app.add_config_value("warnings_filter_config", "", "")
-    app.add_config_value("warnings_filter_silent", True, "")
-
-    app.connect("builder-inited", configure)
-    app.connect("build-finished", finished)
-
-    return {
-        "version": __version__,
-        "parallel_read_safe": True,
-        "parallel_write_safe": True,
-    }
diff --git a/doc/conf.py b/doc/conf.py
index d0280fb560f..fdfdc2c71fe 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -86,7 +86,6 @@ extensions = [
     "zephyr.link-roles",
     "sphinx_tabs.tabs",
     "sphinx_sitemap",
-    "zephyr.warnings_filter",
     "zephyr.doxyrunner",
     "zephyr.doxybridge",
     "zephyr.gh_utils",
@@ -257,10 +256,6 @@ doxybridge_dir = doxyrunner_outdir
 
 html_redirect_pages = redirects.REDIRECTS
 
-# -- Options for zephyr.warnings_filter -----------------------------------
-
-warnings_filter_config = str(ZEPHYR_BASE / "doc" / "known-warnings.txt")
-
 # -- Options for zephyr.link-roles ----------------------------------------
 
 link_roles_manifest_project = "zephyr"
diff --git a/doc/known-warnings.txt b/doc/known-warnings.txt
deleted file mode 100644
index 72ad03d55d5..00000000000
--- a/doc/known-warnings.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-# Each line should contain the regular expression of a known Sphinx warning
-# that should be filtered out