diff --git a/src/west/manifest-schema.yml b/src/west/manifest-schema.yml
index 13188a7..677725d 100644
--- a/src/west/manifest-schema.yml
+++ b/src/west/manifest-schema.yml
@@ -126,6 +126,10 @@ mapping:
           groups:
             required: false
             include: groups-schema
+          # Arbitrary project user data.
+          userdata:
+            required: false
+            type: any
 
   # If present, a list of project groups to enable and disable. Prefix
   # a group name with "-" to disable it; prefix with "+" to enable it.
diff --git a/src/west/manifest.py b/src/west/manifest.py
index ea84d5e..6a7c38a 100644
--- a/src/west/manifest.py
+++ b/src/west/manifest.py
@@ -645,6 +645,7 @@ class Project:
       an empty list.
     - ``submodules``: the project's submodules configuration; either
       a list of Submodule objects, or a boolean.
+    - ``userdata``: the parsed 'userdata' field in the manifest, or None
     '''
 
     def __eq__(self, other):
@@ -656,7 +657,8 @@ class Project:
                 f'clone_depth={self.clone_depth}, '
                 f'west_commands={self.west_commands}, '
                 f'topdir={repr(self.topdir)}, '
-                f'groups={self.groups})')
+                f'groups={repr(self.groups)}, '
+                f'userdata={self.userdata})')
 
     def __str__(self):
         path_repr = repr(self.abspath or self.path)
@@ -670,7 +672,8 @@ class Project:
                  west_commands: Optional[WestCommandsType] = None,
                  topdir: Optional[PathType] = None,
                  remote_name: Optional[str] = None,
-                 groups: Optional[GroupsType] = None):
+                 groups: Optional[GroupsType] = None,
+                 userdata: Optional[Any] = None):
         '''Project constructor.
 
         If *topdir* is ``None``, then absolute path attributes
@@ -702,6 +705,7 @@ class Project:
         self.topdir = os.fspath(topdir) if topdir else None
         self.remote_name = remote_name or 'origin'
         self.groups: GroupsType = groups or []
+        self.userdata: Any = userdata
 
     @property
     def path(self) -> str:
@@ -2026,13 +2030,16 @@ class Manifest:
             self._malformed(
                 f'project {name}: "groups" cannot be combined with "import"')
 
+        userdata = pd.get('userdata')
+
         ret = Project(name, url, pd.get('revision', defaults.revision), path,
                       submodules=self._load_submodules(pd.get('submodules'),
                                                        f'project {name}'),
                       clone_depth=pd.get('clone-depth'),
                       west_commands=pd.get('west-commands'),
                       topdir=self.topdir, remote_name=remote,
-                      groups=groups)
+                      groups=groups,
+                      userdata=userdata)
 
         # Make sure the return Project's path does not escape the
         # workspace. We can't use escapes_directory() as that
diff --git a/tests/test_manifest.py b/tests/test_manifest.py
index a309754..8241e60 100644
--- a/tests/test_manifest.py
+++ b/tests/test_manifest.py
@@ -534,7 +534,7 @@ def test_project_repr():
       west-commands: some-path/west-commands.yml
     ''')
     assert repr(m.projects[1]) == \
-        'Project("zephyr", "https://foo.com", revision="r", path=\'zephyr\', clone_depth=None, west_commands=[\'some-path/west-commands.yml\'], topdir=None, groups=[])'  # noqa: E501
+        'Project("zephyr", "https://foo.com", revision="r", path=\'zephyr\', clone_depth=None, west_commands=[\'some-path/west-commands.yml\'], topdir=None, groups=[], userdata=None)'  # noqa: E501
 
 def test_project_sha(tmpdir):
     tmpdir = Path(os.fspath(tmpdir))
@@ -548,6 +548,26 @@ def test_project_sha(tmpdir):
                       topdir=tmpdir.parent)
     assert project.sha(project.revision) == expected_sha
 
+def test_project_userdata(tmpdir):
+    m = M('''\
+    defaults:
+      remote: r
+    remotes:
+      - name: r
+        url-base: base
+    projects:
+    - name: foo
+    - name: bar
+      userdata: a-string
+    - name: baz
+      userdata:
+        key: value
+    ''')
+    foo, bar, baz = m.get_projects(['foo', 'bar', 'baz'])
+    assert foo.userdata is None
+    assert bar.userdata == 'a-string'
+    assert baz.userdata == {'key': 'value'}
+
 def test_no_projects():
     # An empty projects list is allowed.