She initially joined the Home Fleet and was used for ocean trade protection duties. As part of the 15th Cruiser Squadron she took part in operations against German raiders following the sinking of the armed merchant cruiser in November 1940. During that month she was involved in the destruction of the German weather ship Hinrich Freese off Jan Mayen. In December and January she escorted convoys to Freetown in Sierra Leone, but at the end of January 1941 was back in northern waters where she briefly sighted the German battleships and south of Iceland as they were about to break out into the Atlantic (Operation Berlin). By May 1941 "Naiad" was with Force H in the Mediterranean on Malta convoy operations, and flagship of the 15th Cruiser Squadron. "Naiad" participated in the Crete operations, where she was badly damaged by German aircraft. She subsequently operated against Vichy French forces in Syria, where, together with the cruiser , she engaged the . For the remainder of her service, she was in the Mediterranean, mostly connected with the continual attempts to resupply Malta.