diff --git a/ash/accelerators/accelerator_controller.cc b/ash/accelerators/accelerator_controller.cc
index adf15ef8a343..664de71d5d6a 100644
--- a/ash/accelerators/accelerator_controller.cc
+++ b/ash/accelerators/accelerator_controller.cc
@@ -709,6 +709,7 @@ void HandleToggleVoiceInteraction(const ui::Accelerator& accelerator) {
     case mojom::AssistantAllowedState::DISALLOWED_BY_ARC_DISALLOWED:
     case mojom::AssistantAllowedState::DISALLOWED_BY_FLAG:
     case mojom::AssistantAllowedState::DISALLOWED_BY_SUPERVISED_USER:
+    case mojom::AssistantAllowedState::DISALLOWED_BY_CHILD_USER:
     case mojom::AssistantAllowedState::DISALLOWED_BY_INCOGNITO:
       // TODO(xiaohuic): show a specific toast.
       return;
diff --git a/ash/public/interfaces/voice_interaction_controller.mojom b/ash/public/interfaces/voice_interaction_controller.mojom
index 04589e3adf6f..ccada86fdf2e 100644
--- a/ash/public/interfaces/voice_interaction_controller.mojom
+++ b/ash/public/interfaces/voice_interaction_controller.mojom
@@ -39,6 +39,8 @@ enum AssistantAllowedState {
   DISALLOWED_BY_NONPRIMARY_USER,
   // Disallowed because current user is supervised user.
   DISALLOWED_BY_SUPERVISED_USER,
+  // Disallowed because current user is child user.
+  DISALLOWED_BY_CHILD_USER,
   // Disallowed because incognito mode.
   DISALLOWED_BY_INCOGNITO,
   // Disallowed because the device is in demo mode.
diff --git a/chrome/browser/chromeos/arc/arc_util.cc b/chrome/browser/chromeos/arc/arc_util.cc
index 386f33006e3b..21284a6e9e5a 100644
--- a/chrome/browser/chromeos/arc/arc_util.cc
+++ b/chrome/browser/chromeos/arc/arc_util.cc
@@ -597,6 +597,9 @@ ash::mojom::AssistantAllowedState IsAssistantAllowedForProfile(
   if (profile->IsLegacySupervised())
     return ash::mojom::AssistantAllowedState::DISALLOWED_BY_SUPERVISED_USER;
 
+  if (profile->IsChild())
+    return ash::mojom::AssistantAllowedState::DISALLOWED_BY_CHILD_USER;
+
   if (chromeos::DemoSession::IsDeviceInDemoMode())
     return ash::mojom::AssistantAllowedState::DISALLOWED_BY_DEMO_MODE;
 
diff --git a/chrome/browser/chromeos/arc/arc_util_unittest.cc b/chrome/browser/chromeos/arc/arc_util_unittest.cc
index 426c5ad73093..c3d89dfd5aff 100644
--- a/chrome/browser/chromeos/arc/arc_util_unittest.cc
+++ b/chrome/browser/chromeos/arc/arc_util_unittest.cc
@@ -29,6 +29,7 @@
 #include "chrome/browser/policy/profile_policy_connector.h"
 #include "chrome/browser/policy/profile_policy_connector_factory.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/supervised_user/supervised_user_constants.h"
 #include "chrome/test/base/testing_browser_process.h"
 #include "chrome/test/base/testing_profile.h"
 #include "chrome/test/base/testing_profile_manager.h"
@@ -531,6 +532,18 @@ TEST_F(ChromeArcUtilTest, IsAssistantAllowedForProfile_SupervisedUser) {
             IsAssistantAllowedForProfile(profile()));
 }
 
+TEST_F(ChromeArcUtilTest, IsAssistantAllowedForProfile_ChildUser) {
+  base::CommandLine::ForCurrentProcess()->InitFromArgv(
+      {"", "--arc-availability=officially-supported",
+       "--enable-voice-interaction"});
+  ScopedLogIn login(GetFakeUserManager(),
+                    AccountId::FromUserEmailGaiaId(
+                        profile()->GetProfileUserName(), kTestGaiaId));
+  profile()->SetSupervisedUserId(supervised_users::kChildAccountSUID);
+  EXPECT_EQ(ash::mojom::AssistantAllowedState::DISALLOWED_BY_CHILD_USER,
+            IsAssistantAllowedForProfile(profile()));
+}
+
 TEST_F(ChromeArcUtilTest, IsAssistantAllowedForProfile_Locale) {
   profile()->GetTestingPrefService()->SetString(
       language::prefs::kApplicationLocale, "he");