diff --git a/server/migrations/20250918-add-tenant-id-to-drone-detections.js b/server/migrations/20250918-add-tenant-id-to-drone-detections.js
new file mode 100644
index 0000000..5e80650
--- /dev/null
+++ b/server/migrations/20250918-add-tenant-id-to-drone-detections.js
@@ -0,0 +1,91 @@
+'use strict';
+
+module.exports = {
+  async up(queryInterface, Sequelize) {
+    // Add tenant_id column to drone_detections table
+    try {
+      await queryInterface.addColumn('drone_detections', 'tenant_id', {
+        type: Sequelize.UUID,
+        allowNull: true,
+        references: {
+          model: 'tenants',
+          key: 'id'
+        },
+        comment: 'Tenant ID for multi-tenant isolation'
+      });
+      
+      console.log('✅ Added tenant_id column to drone_detections table');
+    } catch (error) {
+      if (error.original && error.original.code === '42701') {
+        // Column already exists
+        console.log('ℹ️  tenant_id column already exists in drone_detections table');
+      } else {
+        throw error;
+      }
+    }
+
+    // Add index for better query performance
+    try {
+      await queryInterface.addIndex('drone_detections', ['tenant_id'], {
+        name: 'idx_drone_detections_tenant_id'
+      });
+      console.log('✅ Added index on tenant_id column');
+    } catch (error) {
+      if (error.original && error.original.code === '42P07') {
+        // Index already exists
+        console.log('ℹ️  Index on tenant_id already exists');
+      } else {
+        throw error;
+      }
+    }
+
+    // Add foreign key constraint
+    try {
+      await queryInterface.addConstraint('drone_detections', {
+        fields: ['tenant_id'],
+        type: 'foreign key',
+        name: 'fk_drone_detections_tenant_id',
+        references: {
+          table: 'tenants',
+          field: 'id'
+        },
+        onDelete: 'SET NULL',
+        onUpdate: 'CASCADE'
+      });
+      console.log('✅ Added foreign key constraint for tenant_id');
+    } catch (error) {
+      if (error.original && error.original.code === '42710') {
+        // Constraint already exists
+        console.log('ℹ️  Foreign key constraint already exists');
+      } else {
+        throw error;
+      }
+    }
+  },
+
+  async down(queryInterface, Sequelize) {
+    // Remove foreign key constraint
+    try {
+      await queryInterface.removeConstraint('drone_detections', 'fk_drone_detections_tenant_id');
+      console.log('✅ Removed foreign key constraint for tenant_id');
+    } catch (error) {
+      console.log('ℹ️  Foreign key constraint already removed or does not exist');
+    }
+
+    // Remove index
+    try {
+      await queryInterface.removeIndex('drone_detections', 'idx_drone_detections_tenant_id');
+      console.log('✅ Removed index on tenant_id column');
+    } catch (error) {
+      console.log('ℹ️  Index already removed or does not exist');
+    }
+
+    // Remove tenant_id column
+    try {
+      await queryInterface.removeColumn('drone_detections', 'tenant_id');
+      console.log('✅ Removed tenant_id column from drone_detections table');
+    } catch (error) {
+      console.log('ℹ️  tenant_id column already removed or does not exist');
+    }
+  }
+};
\ No newline at end of file