diff --git a/command.py b/command.py
index 7da063a25..bfafcd449 100644
--- a/command.py
+++ b/command.py
@@ -17,6 +17,7 @@ import multiprocessing
 import optparse
 import os
 import re
+from typing import TYPE_CHECKING
 
 from error import InvalidProjectGroupsError
 from error import NoSuchProjectError
@@ -25,6 +26,10 @@ from event_log import EventLog
 import progress
 
 
+if TYPE_CHECKING:
+    from project import Project
+
+
 # Are we generating man-pages?
 GENERATE_MANPAGES = os.environ.get("_REPO_GENERATE_MANPAGES_") == " indeed! "
 
@@ -375,7 +380,7 @@ class Command:
         manifest=None,
         groups="",
         missing_ok=False,
-        submodules_ok=False,
+        submodules_ok=None,
         all_manifests=False,
     ):
         """A list of projects that match the arguments.
@@ -385,7 +390,9 @@ class Command:
             manifest: an XmlManifest, the manifest to use, or None for default.
             groups: a string, the manifest groups in use.
             missing_ok: a boolean, whether to allow missing projects.
-            submodules_ok: a boolean, whether to allow submodules.
+            submodules_ok: whether to allow submodules. True allows them for
+                all projects, False disallows them for all projects, and None
+                defers to each project's sync-s setting.
             all_manifests: a boolean, if True then all manifests and
                 submanifests are used. If False, then only the local
                 (sub)manifest is used.
@@ -403,6 +410,11 @@ class Command:
             all_projects_list = manifest.projects
         result = []
 
+        def should_include_submodules(project: "Project") -> bool:
+            if submodules_ok is None:
+                return project.sync_s
+            return submodules_ok
+
         if not groups:
             groups = manifest.GetManifestGroupsStr()
         groups = [x for x in re.split(r"[,\s]+", groups) if x]
@@ -410,7 +422,7 @@ class Command:
         if not args:
             derived_projects = {}
             for project in all_projects_list:
-                if submodules_ok or project.sync_s:
+                if should_include_submodules(project):
                     derived_projects.update(
                         (p.RelPath(local=False), p)
                         for p in project.GetDerivedSubprojects()
@@ -452,7 +464,7 @@ class Command:
                     if (
                         project
                         and not project.Derived
-                        and (submodules_ok or project.sync_s)
+                        and should_include_submodules(project)
                     ):
                         search_again = False
                         for subproject in project.GetDerivedSubprojects():
diff --git a/completion.zsh b/completion.zsh
index 507ed2bb2..8c0322f77 100644
--- a/completion.zsh
+++ b/completion.zsh
@@ -323,6 +323,7 @@ _repo() {
         '(-u --manifest-server-username)'{-u,--manifest-server-username=}'[Username for manifest server]:username:' \
         '(-p --manifest-server-password)'{-p,--manifest-server-password=}'[Password for manifest server]:password:' \
         '--fetch-submodules[Fetch submodules]' \
+        '--no-fetch-submodules[Do not fetch submodules]' \
         '--use-superproject[Use superproject]' \
         '--no-use-superproject[Do not use superproject]' \
         '--tags[Sync tags]' \
diff --git a/man/repo-smartsync.1 b/man/repo-smartsync.1
index ef4c112df..07bab536b 100644
--- a/man/repo-smartsync.1
+++ b/man/repo-smartsync.1
@@ -83,6 +83,9 @@ password to authenticate with the manifest server
 \fB\-\-fetch\-submodules\fR
 fetch submodules from server
 .TP
+\fB\-\-no\-fetch\-submodules\fR
+don't fetch submodules from server
+.TP
 \fB\-\-use\-superproject\fR
 use the manifest superproject to sync projects; implies \fB\-c\fR
 .TP
diff --git a/man/repo-sync.1 b/man/repo-sync.1
index 43d959500..68d1e5e6a 100644
--- a/man/repo-sync.1
+++ b/man/repo-sync.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH REPO "1" "June 2026" "repo sync" "Repo Manual"
+.TH REPO "1" "July 2026" "repo sync" "Repo Manual"
 .SH NAME
 repo \- repo sync - manual page for repo sync
 .SH SYNOPSIS
@@ -83,6 +83,9 @@ password to authenticate with the manifest server
 \fB\-\-fetch\-submodules\fR
 fetch submodules from server
 .TP
+\fB\-\-no\-fetch\-submodules\fR
+don't fetch submodules from server
+.TP
 \fB\-\-use\-superproject\fR
 use the manifest superproject to sync projects; implies \fB\-c\fR
 .TP
@@ -212,8 +215,9 @@ bootstrap a new Git repository from a resumeable bundle file on a content
 delivery network. This may be necessary if there are problems with the local
 Python HTTP client or proxy configuration, but the Git binary works.
 .PP
-The \fB\-\-fetch\-submodules\fR option enables fetching Git submodules of a project from
-server.
+The \fB\-\-fetch\-submodules\fR option enables fetching Git submodules of all projects
+from the server. The \fB\-\-no\-fetch\-submodules\fR option disables fetching Git
+submodules, even when a project has sync\-s="true" in the manifest.
 .PP
 The \fB\-c\fR/\-\-current\-branch option can be used to only fetch objects that are on the
 branch specified by a project's revision.
diff --git a/subcmds/sync.py b/subcmds/sync.py
index 2b9cafe2d..5a635fa97 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -379,7 +379,8 @@ may be necessary if there are problems with the local Python
 HTTP client or proxy configuration, but the Git binary works.
 
 The --fetch-submodules option enables fetching Git submodules
-of a project from server.
+of all projects from the server. The --no-fetch-submodules option disables
+fetching Git submodules, even when a project has sync-s="true" in the manifest.
 
 The -c/--current-branch option can be used to only fetch objects that
 are on the branch specified by a project's revision.
@@ -573,6 +574,12 @@ later is required to fix a server side protocol bug.
             action="store_true",
             help="fetch submodules from server",
         )
+        p.add_option(
+            "--no-fetch-submodules",
+            dest="fetch_submodules",
+            action="store_false",
+            help="don't fetch submodules from server",
+        )
         p.add_option(
             "--use-superproject",
             action="store_true",
diff --git a/tests/test_command.py b/tests/test_command.py
index bd2a47f71..d7938c5f2 100644
--- a/tests/test_command.py
+++ b/tests/test_command.py
@@ -14,6 +14,8 @@
 
 """Unittests for the command.py module."""
 
+import pytest
+
 from command import Command
 
 
@@ -86,3 +88,32 @@ def test_get_projects_keeps_derived_subprojects_for_repeated_repo():
     projects = cmd.GetProjects([])
 
     assert set(projects) == {project_a, project_b, submodule_a, submodule_b}
+
+
+@pytest.mark.parametrize(
+    "submodules_ok, sync_s, includes_submodule",
+    [
+        (None, False, False),
+        (None, True, True),
+        (True, False, True),
+        (True, True, True),
+        (False, False, False),
+        (False, True, False),
+    ],
+)
+def test_get_projects_submodule_override(
+    submodules_ok, sync_s, includes_submodule
+):
+    """The CLI override takes precedence over a project's sync-s setting."""
+    submodule = FakeProject("submodule", "project/submodule")
+    project = FakeProject(
+        "project",
+        "project",
+        derived_subprojects=[submodule],
+        sync_s=sync_s,
+    )
+    cmd = Command(manifest=FakeManifest([project]))
+
+    projects = cmd.GetProjects([], submodules_ok=submodules_ok)
+
+    assert (submodule in projects) is includes_submodule
diff --git a/tests/test_subcmds_sync.py b/tests/test_subcmds_sync.py
index f8588465c..1fb462a60 100644
--- a/tests/test_subcmds_sync.py
+++ b/tests/test_subcmds_sync.py
@@ -30,6 +30,23 @@ from project import SyncNetworkHalfResult
 from subcmds import sync
 
 
+@pytest.mark.parametrize(
+    "cli_args, expected",
+    [
+        ([], None),
+        (["--fetch-submodules"], True),
+        (["--no-fetch-submodules"], False),
+    ],
+)
+def test_fetch_submodules_option(cli_args, expected):
+    """The fetch-submodules flags preserve an unset manifest-driven state."""
+    cmd = sync.Sync()
+
+    opts, _ = cmd.OptionParser.parse_args(cli_args)
+
+    assert opts.fetch_submodules is expected
+
+
 @pytest.mark.parametrize(
     "use_superproject, cli_args, result",
     [