diff --git a/app/api/qr_auth.py b/app/api/qr_auth.py
index 8f891e4e..97aadb94 100644
--- a/app/api/qr_auth.py
+++ b/app/api/qr_auth.py
@@ -31,6 +31,7 @@ from pydantic import BaseModel, Field
 from sqlalchemy.orm import Session
 
 from app.auth import require_login
+from app.config import settings
 from app.database import get_db
 from app.middleware.audit_log import get_client_ip
 from app.utils.session_manager import (
@@ -151,6 +152,11 @@ async def create_challenge(
     displayed to the user.  The mobile app scans this QR code and
     calls the ``/claim`` endpoint.
     """
+    if not settings.qr_login_enabled:
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail="QR login feature is currently disabled. Please contact your administrator to enable it.",
+        )
     ip = get_client_ip(request)
     challenge = create_qr_challenge(db, owner_id, ip_address=ip)
 
@@ -187,6 +193,11 @@ async def poll_challenge_status(
     The web UI calls this endpoint every few seconds to check if the
     mobile app has scanned the QR code and claimed the challenge.
     """
+    if not settings.qr_login_enabled:
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail="QR login feature is currently disabled. Please contact your administrator to enable it.",
+        )
     result = get_challenge_status(db, challenge_id, owner_id)
     if not result:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Challenge not found")
@@ -206,6 +217,11 @@ async def claim_challenge(
     serves as proof that the user authorized this login from their web
     session.
     """
+    if not settings.qr_login_enabled:
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail="QR login feature is currently disabled. Please contact your administrator to enable it.",
+        )
     ip = get_client_ip(request)
     result = claim_qr_challenge(db, body.challenge_token, device_name=body.device_name, ip_address=ip)
 
diff --git a/app/config.py b/app/config.py
index aabfdff0..85631fb8 100644
--- a/app/config.py
+++ b/app/config.py
@@ -244,6 +244,10 @@ class Settings(BaseSettings):
             "Useful for admin-configured non-standard durations."
         ),
     )
+    qr_login_enabled: bool = Field(
+        default=True,
+        description="Enable QR code-based login for mobile device authentication (default: True).",
+    )
     qr_login_challenge_ttl_seconds: int = Field(
         default=120,
         description="Time-to-live in seconds for QR login challenges (default: 2 minutes).",
diff --git a/app/utils/settings_service.py b/app/utils/settings_service.py
index e4961dab..e5d37985 100644
--- a/app/utils/settings_service.py
+++ b/app/utils/settings_service.py
@@ -206,6 +206,14 @@ SETTING_METADATA = {
         "required": False,
         "restart_required": True,
     },
+    "qr_login_enabled": {
+        "category": "Authentication",
+        "description": "Enable QR code-based login for mobile device authentication.",
+        "type": "boolean",
+        "sensitive": False,
+        "required": False,
+        "restart_required": False,
+    },
     "qr_login_challenge_ttl_seconds": {
         "category": "Authentication",
         "description": "Time-to-live in seconds for QR login challenges (default 120).",
diff --git a/app/views/settings.py b/app/views/settings.py
index a026a124..85307a82 100644
--- a/app/views/settings.py
+++ b/app/views/settings.py
@@ -464,7 +464,7 @@ async def connections_page(request: Request, db: Session = Depends(get_db)):
 
         # Feature toggles
         sso_auto_login = _is_truthy(_get_effective("sso_auto_login"))
-        qr_login_enabled = _is_truthy(_get_effective("qr_login_challenge_ttl_seconds"))
+        qr_login_enabled = _is_truthy(_get_effective("qr_login_enabled"))
         frontend_url_configured = bool(_get_effective("public_base_url"))
 
         return templates.TemplateResponse(
diff --git a/frontend/templates/admin_connections.html b/frontend/templates/admin_connections.html
index 3e9db7c2..232663ac 100644
--- a/frontend/templates/admin_connections.html
+++ b/frontend/templates/admin_connections.html
@@ -46,7 +46,8 @@
       <div>
         <label class="relative inline-flex items-center cursor-pointer">
           <input type="checkbox" id="qr-upload-toggle" class="sr-only peer"
-                 {% if qr_login_enabled %}checked{% endif %} disabled>
+                 {% if qr_login_enabled %}checked{% endif %}
+                 onchange="toggleSetting('qr_login_enabled', this.checked)">
           <div class="w-11 h-6 bg-gray-200 peer-focus:outline-none peer-focus:ring-2 peer-focus:ring-indigo-500 rounded-full peer dark:bg-gray-700 peer-checked:after:translate-x-full peer-checked:after:border-white after:content-[''] after:absolute after:top-[2px] after:left-[2px] after:bg-white after:border-gray-300 after:border after:rounded-full after:h-5 after:w-5 after:transition-all dark:border-gray-600 peer-checked:bg-indigo-600" style="min-width:44px; min-height:24px;"></div>
           <span class="ml-3 text-sm font-medium text-gray-700 dark:text-gray-300">{{ _("connections.qr_code_enabled") }}</span>
         </label>