diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index 696eb8aee125..ff8d7d379949 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -4,7 +4,7 @@
 
 <!--
 Checklist:
-- Read the [Contributing Guidelines](https://github.com/python/mypy/blob/master/CONTRIBUTING.md)
+- Read the [Contributing Guidelines](https://github.com/python/mypy/blob/main/CONTRIBUTING.md)
 - Add tests for all changed behaviour.
 - If you can't add a test, please explain why and how you verified your changes work.
 - Make sure CI passes.
diff --git a/.github/workflows/build_wheels.yml b/.github/workflows/build_wheels.yml
index 8055cfd24180..37648d912add 100644
--- a/.github/workflows/build_wheels.yml
+++ b/.github/workflows/build_wheels.yml
@@ -2,7 +2,7 @@ name: Trigger wheel build
 
 on:
   push:
-    branches: [main, master, 'release*']
+    branches: [main, 'release*']
     tags: ['*']
 
 permissions:
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index 923d74a02f71..5d185984f29c 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -3,7 +3,7 @@ name: Check documentation build
 on:
   workflow_dispatch:
   push:
-    branches: [main, master, 'release*']
+    branches: [main, 'release*']
     tags: ['*']
   pull_request:
     paths:
diff --git a/.github/workflows/mypy_primer.yml b/.github/workflows/mypy_primer.yml
index 0c77d3a255d8..3e3418595ed3 100644
--- a/.github/workflows/mypy_primer.yml
+++ b/.github/workflows/mypy_primer.yml
@@ -1,7 +1,7 @@
 name: Run mypy_primer
 
 on:
-  # Only run on PR, since we diff against master
+  # Only run on PR, since we diff against main
   pull_request:
     paths-ignore:
     - 'docs/**'
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 4150d1968bfb..458b9a817e50 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -3,7 +3,7 @@ name: Tests
 on:
   workflow_dispatch:
   push:
-    branches: [main, master, 'release*']
+    branches: [main, 'release*']
     tags: ['*']
   pull_request:
     paths-ignore:
diff --git a/.github/workflows/test_stubgenc.yml b/.github/workflows/test_stubgenc.yml
index 519f63ac2bd7..feb41c824a8e 100644
--- a/.github/workflows/test_stubgenc.yml
+++ b/.github/workflows/test_stubgenc.yml
@@ -3,7 +3,7 @@ name: Test stubgenc on pybind11_fixtures
 on:
   workflow_dispatch:
   push:
-    branches: [main, master, 'release*']
+    branches: [main, 'release*']
     tags: ['*']
   pull_request:
     paths:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4522465a484d..56acca8795a6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1075,7 +1075,7 @@ This feature was contributed by Ivan Levkivskyi (PR [16237](https://github.com/p
 
 ### Mypy Changelog
 
-We now maintain a [changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md) in the mypy Git repository. It mirrors the contents of [mypy release blog posts](https://mypy-lang.blogspot.com/). We will continue to also publish release blog posts. In the future, release blog posts will be created based on the changelog near a release date.
+We now maintain a [changelog](https://github.com/python/mypy/blob/main/CHANGELOG.md) in the mypy Git repository. It mirrors the contents of [mypy release blog posts](https://mypy-lang.blogspot.com/). We will continue to also publish release blog posts. In the future, release blog posts will be created based on the changelog near a release date.
 
 This was contributed by Shantanu (PR [16280](https://github.com/python/mypy/pull/16280)).
 
diff --git a/CREDITS b/CREDITS
index fb2fe155a9b8..120e67d9c1ef 100644
--- a/CREDITS
+++ b/CREDITS
@@ -2,7 +2,7 @@ Credits
 -------
 
 For a full list of contributors you can mine the commit history:
-https://github.com/python/mypy/commits/master
+https://github.com/python/mypy/commits/main
 
 For lists of contributors per mypy release (including typeshed) see
 the release blog posts at https://mypy-lang.blogspot.com/.
diff --git a/README.md b/README.md
index 07c170d46cb3..976d66b4e2a6 100644
--- a/README.md
+++ b/README.md
@@ -102,7 +102,7 @@ repo directly:
 ```bash
 python3 -m pip install -U git+https://github.com/python/mypy.git
 # or if you don't have 'git' installed
-python3 -m pip install -U https://github.com/python/mypy/zipball/master
+python3 -m pip install -U https://github.com/python/mypy/zipball/main
 ```
 
 Now you can type-check the [statically typed parts] of a program like this:
diff --git a/docs/source/additional_features.rst b/docs/source/additional_features.rst
index e7c162a0b0df..1b63b46aba78 100644
--- a/docs/source/additional_features.rst
+++ b/docs/source/additional_features.rst
@@ -263,7 +263,7 @@ Your CI script might work like this:
 
 * Create a tarball from the ``.mypy_cache`` directory.
 
-* Determine the current git master branch commit id (say, using
+* Determine the current git main branch commit id (say, using
   ``git rev-parse HEAD``).
 
 * Upload the tarball to the shared repository with a name derived from the
@@ -278,13 +278,13 @@ populates the local ``.mypy_cache`` directory from the shared
 repository and then runs a normal incremental build.
 
 The wrapper script needs some logic to determine the most recent
-central repository commit (by convention, the ``origin/master`` branch
+central repository commit (by convention, the ``origin/main`` branch
 for git) the local development branch is based on. In a typical git
 setup you can do it like this:
 
 .. code::
 
-    git merge-base HEAD origin/master
+    git merge-base HEAD origin/main
 
 The next step is to download the cache data (contents of the
 ``.mypy_cache`` directory) from the shared repository based on the
@@ -331,11 +331,11 @@ at least if your codebase is hundreds of thousands of lines or more:
   potentially large number of changes in an incremental build, as this can
   be much slower than downloading cache data and restarting the daemon.
 
-* If the current local branch is based on a very recent master commit,
+* If the current local branch is based on a very recent main commit,
   the remote cache data may not yet be available for that commit, as
   there will necessarily be some latency to build the cache files. It
   may be a good idea to look for cache data for, say, the 5 latest
-  master commits and use the most recent data that is available.
+  main commits and use the most recent data that is available.
 
 * If the remote cache is not accessible for some reason (say, from a public
   network), the script can still fall back to a normal incremental build.
diff --git a/docs/source/conf.py b/docs/source/conf.py
index 7f5fe9d43d5f..21e7fc094699 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -109,7 +109,7 @@
 
 html_theme_options = {
     "source_repository": "https://github.com/python/mypy",
-    "source_branch": "master",
+    "source_branch": "main",
     "source_directory": "docs/source",
 }
 
diff --git a/docs/source/extending_mypy.rst b/docs/source/extending_mypy.rst
index bded07319b64..18b07c7e73d0 100644
--- a/docs/source/extending_mypy.rst
+++ b/docs/source/extending_mypy.rst
@@ -93,9 +93,9 @@ can be specified after colon:
 
 In the following sections we describe the basics of the plugin system with
 some examples. For more technical details, please read the docstrings in
-`mypy/plugin.py <https://github.com/python/mypy/blob/master/mypy/plugin.py>`_
+`mypy/plugin.py <https://github.com/python/mypy/blob/main/mypy/plugin.py>`_
 in mypy source code. Also you can find good examples in the bundled plugins
-located in `mypy/plugins <https://github.com/python/mypy/tree/master/mypy/plugins>`_.
+located in `mypy/plugins <https://github.com/python/mypy/tree/main/mypy/plugins>`_.
 
 High-level overview
 *******************
diff --git a/docs/source/index.rst b/docs/source/index.rst
index de3286d58ace..7219020f64dc 100644
--- a/docs/source/index.rst
+++ b/docs/source/index.rst
@@ -1,4 +1,4 @@
-.. Mypy documentation master file, created by
+.. Mypy documentation main file, created by
    sphinx-quickstart on Sun Sep 14 19:50:35 2014.
    You can adapt this file completely to your liking, but it should at least
    contain the root `toctree` directive.
diff --git a/misc/generate_changelog.py b/misc/generate_changelog.py
index ebab6c569152..051a36076b79 100644
--- a/misc/generate_changelog.py
+++ b/misc/generate_changelog.py
@@ -99,7 +99,7 @@ def filter_omitted_commits(commits: list[CommitInfo]) -> list[CommitInfo]:
 def normalize_title(title: str) -> str:
     # We sometimes add a title prefix when cherry-picking commits to a
     # release branch. Attempt to remove these prefixes so that we can
-    # match them to the corresponding master branch.
+    # match them to the corresponding main branch.
     if m := re.match(r"\[release [0-9.]+\] *", title, flags=re.I):
         title = title.replace(m.group(0), "")
     return title
diff --git a/misc/perf_compare.py b/misc/perf_compare.py
index be05bb6ddc32..1d292488d1a5 100644
--- a/misc/perf_compare.py
+++ b/misc/perf_compare.py
@@ -2,7 +2,7 @@
 
 Simple usage:
 
-  python misc/perf_compare.py my-branch master ...
+  python misc/perf_compare.py my-branch main ...
 
 What this does:
 
diff --git a/misc/trigger_wheel_build.sh b/misc/trigger_wheel_build.sh
index c914a6e7cf86..f4874749f902 100755
--- a/misc/trigger_wheel_build.sh
+++ b/misc/trigger_wheel_build.sh
@@ -19,5 +19,5 @@ cd build
 echo $COMMIT > mypy_commit
 git commit -am "Build wheels for mypy $V"
 git tag v$V
-# Push a tag, but no need to push the change to master
+# Push a tag, but no need to push the change to main
 git push --tags
diff --git a/mypy/errors.py b/mypy/errors.py
index 1b3f485d19c0..54ee2ed10bf9 100644
--- a/mypy/errors.py
+++ b/mypy/errors.py
@@ -1261,7 +1261,7 @@ def report_internal_error(
     # Print "INTERNAL ERROR" message.
     print(
         f"{prefix}error: INTERNAL ERROR --",
-        "Please try using mypy master on GitHub:\n"
+        "Please try using mypy main on GitHub:\n"
         "https://mypy.readthedocs.io/en/stable/common_issues.html"
         "#using-a-development-mypy-build",
         file=stderr,
@@ -1270,7 +1270,7 @@ def report_internal_error(
         print("Please report a bug at https://github.com/python/mypy/issues", file=stderr)
     else:
         print(
-            "If this issue continues with mypy master, "
+            "If this issue continues with mypy main, "
             "please report a bug at https://github.com/python/mypy/issues",
             file=stderr,
         )
diff --git a/mypyc/doc/dev-intro.md b/mypyc/doc/dev-intro.md
index 461a19d37121..e7b1a91074e8 100644
--- a/mypyc/doc/dev-intro.md
+++ b/mypyc/doc/dev-intro.md
@@ -63,7 +63,7 @@ features.
 ## Development Environment
 
 First you should set up the mypy development environment as described in
-the [mypy docs](https://github.com/python/mypy/blob/master/README.md).
+the [mypy docs](https://github.com/python/mypy/blob/main/README.md).
 macOS, Linux and Windows are supported.
 
 ## Compiling and Running Programs
diff --git a/mypyc/doc/index.rst b/mypyc/doc/index.rst
index 5b1cc48fab3d..c3edcdf24f62 100644
--- a/mypyc/doc/index.rst
+++ b/mypyc/doc/index.rst
@@ -1,4 +1,4 @@
-.. mypyc documentation master file, created by
+.. mypyc documentation main file, created by
    sphinx-quickstart on Sun Apr  5 14:01:55 2020.
    You can adapt this file completely to your liking, but it should at least
    contain the root `toctree` directive.
diff --git a/setup.py b/setup.py
index a50afde4ce6b..3285099a7bbf 100644
--- a/setup.py
+++ b/setup.py
@@ -238,7 +238,7 @@ def run(self):
     project_urls={
         "Documentation": "https://mypy.readthedocs.io/en/stable/index.html",
         "Repository": "https://github.com/python/mypy",
-        "Changelog": "https://github.com/python/mypy/blob/master/CHANGELOG.md",
+        "Changelog": "https://github.com/python/mypy/blob/main/CHANGELOG.md",
         "Issues": "https://github.com/python/mypy/issues",
     },
 )