diff --git a/truewiki/__main__.py b/truewiki/__main__.py
index e83072d..7497e38 100644
--- a/truewiki/__main__.py
+++ b/truewiki/__main__.py
@@ -21,6 +21,7 @@
 from .storage.local import click_storage_local
 from .user.github import click_user_github
 from .user.gitlab import click_user_gitlab
+from .user.microsoft import click_user_microsoft
 from .user_session import (
     click_user_session,
     get_user_by_bearer,
@@ -122,6 +123,7 @@ async def wait_for_storage():
 @click_user_session
 @click_user_github
 @click_user_gitlab
+@click_user_microsoft
 @click_page
 @click.option("--validate-all", help="Validate all mediawiki files and report all errors", is_flag=True)
 def main(bind, port, storage, frontend_url, cache_time, validate_all):
diff --git a/truewiki/user/base_oauth2.py b/truewiki/user/base_oauth2.py
index 5f4a7c2..55a1000 100644
--- a/truewiki/user/base_oauth2.py
+++ b/truewiki/user/base_oauth2.py
@@ -93,7 +93,8 @@ async def get_user_information(self, code):
 
         user, _ = await self._oauth2.user_info()
 
-        self.display_name = user.username
+        self.display_name = user.username or user.email
+        self.email = user.email
         self.id = str(user.id)
 
         return True
diff --git a/truewiki/user/microsoft.py b/truewiki/user/microsoft.py
new file mode 100644
index 0000000..ca95280
--- /dev/null
+++ b/truewiki/user/microsoft.py
@@ -0,0 +1,57 @@
+import click
+
+from aiohttp import web
+from aioauth_client import MicrosoftClient
+from openttd_helpers import click_helper
+from typing import Tuple
+
+from .base_oauth2 import User as BaseUser
+
+
+MICROSOFT_CLIENT_ID = None
+MICROSOFT_CLIENT_SECRET = None
+
+
+@click_helper.extend
+@click.option("--user-microsoft-client-id", help="Microsoft client ID. (user=microsoft only)")
+@click.option(
+    "--user-microsoft-client-secret",
+    help="Microsoft client secret. Always use this via an environment variable! (user=microsoft only)",
+)
+def click_user_microsoft(user_microsoft_client_id, user_microsoft_client_secret):
+    global MICROSOFT_CLIENT_ID, MICROSOFT_CLIENT_SECRET
+
+    MICROSOFT_CLIENT_ID = user_microsoft_client_id
+    MICROSOFT_CLIENT_SECRET = user_microsoft_client_secret
+
+
+class User(BaseUser):
+    routes = web.RouteTableDef()
+    method = "microsoft"
+    scope = "https://graph.microsoft.com/User.Read"
+
+    def __init__(self, redirect_uri):
+        super().__init__(redirect_uri)
+
+        if not MICROSOFT_CLIENT_ID or not MICROSOFT_CLIENT_SECRET:
+            raise Exception("MICROSOFT_CLIENT_ID and MICROSOFT_CLIENT_SECRET should be set via environment")
+
+        self._oauth2 = MicrosoftClient(client_id=MICROSOFT_CLIENT_ID, client_secret=MICROSOFT_CLIENT_SECRET)
+
+    def get_git_author(self) -> Tuple[str, str]:
+        # Microsoft doesn't supply anonymous email address to refer to a user.
+        return (self.display_name, self.email)
+
+    @staticmethod
+    @routes.get("/user/microsoft-callback")
+    async def login_microsoft_callback(request):
+        return await BaseUser.login_oauth2_callback(request)
+
+    @staticmethod
+    def get_description():
+        return "Login via Microsoft"
+
+    @staticmethod
+    def get_settings_url():
+        # Microsoft doesn't appear to have a single settings page to revoke app permissions.
+        return ""
diff --git a/truewiki/user_session.py b/truewiki/user_session.py
index c234e07..ced8800 100644
--- a/truewiki/user_session.py
+++ b/truewiki/user_session.py
@@ -148,7 +148,7 @@ async def user_logout(request):
 @click.option(
     "--user",
     help="User backend to use (can have multiple).",
-    type=click.Choice(["developer", "github", "gitlab"], case_sensitive=False),
+    type=click.Choice(["developer", "github", "gitlab", "microsoft"], case_sensitive=False),
     required=True,
     multiple=True,
     callback=click_helper.import_module("truewiki.user", "User"),