On 15 August 1941, No. 135 reformed at RAF Baginton with Hurricanes and became operational on 3 October for a month. The Squadron then moved to India arriving early in January to be immediately re-routed to Rangoon where it began operations on 26 January 1942 against Japanese aircraft attacking the area. The Squadron's ground echelon was evacuated to Calcutta when the Japanese attacked Burma during which its aircraft were almost entirely lost. Reformed at Calcutta, the Squadron began flying convoy patrols and in January 1943 began air defence duties and sweeps over Burma which lasted until No. 135 was withdrawn to southern India at the end of May.
After acting as a conversion unit for Blenheim Squadrons being re-equipped with Hurricanes, it provided air defence of the area until it was re-equipped with Thunderbolts, the first arriving in May 1944 and conversion being completed by the end of August. On 16 October 1944, ground attack missions were resumed over Burma and continued until May 1945, when No. 135 was withdrawn from operations and became No. 615 Squadron on 10 June 1945.