diff --git a/backend/app.py b/backend/app.py
index bd5935e..42aba17 100644
--- a/backend/app.py
+++ b/backend/app.py
@@ -1248,7 +1248,7 @@ def admin_user_detail(user_id):
 
         # 2. 사용자 기본 정보 조회
         cursor.execute("""
-            SELECT id, nickname, phone, mileage_balance, created_at
+            SELECT id, nickname, phone, mileage_balance, created_at, birthday
             FROM users WHERE id = ?
         """, (user_id,))
         user = cursor.fetchone()
@@ -1477,7 +1477,8 @@ def admin_user_detail(user_id):
                 'phone': user['phone'],
                 'balance': user['mileage_balance'],
                 'created_at': utc_to_kst_str(user['created_at']),
-                'is_kakao_verified': user['nickname'] != '고객'  # 카카오 인증 여부
+                'is_kakao_verified': user['nickname'] != '고객',  # 카카오 인증 여부
+                'birthday': user['birthday'] if user['birthday'] else None
             },
             'mileage_history': [
                 {
diff --git a/backend/templates/admin.html b/backend/templates/admin.html
index 6599b28..6e99e1d 100644
--- a/backend/templates/admin.html
+++ b/backend/templates/admin.html
@@ -882,6 +882,12 @@
                             <div style="color: #868e96; font-size: 13px; margin-bottom: 6px;">가입일</div>
                             <div style="color: #212529; font-size: 16px; font-weight: 600;">${user.created_at}</div>
                         </div>
+                        ${user.birthday ? `
+                        <div>
+                            <div style="color: #868e96; font-size: 13px; margin-bottom: 6px;">🎂 생일</div>
+                            <div style="color: #ec4899; font-size: 16px; font-weight: 600;">${user.birthday.slice(0,2)}월 ${user.birthday.slice(2,4)}일</div>
+                        </div>
+                        ` : ''}
                     </div>
                     <div style="text-align: right; display: flex; gap: 8px; justify-content: flex-end;">
                         <button onclick="showAIAnalysisModal(${user.id})" style="padding: 10px 24px; background: linear-gradient(135deg, #8b5cf6 0%, #6366f1 100%); color: white; border: none; border-radius: 10px; font-size: 14px; font-weight: 600; cursor: pointer; transition: all 0.2s;">