On 15 March 1937, No. 217 reformed as a general reconnaissance squadron at Boscombe Down equipped with Ansons. On the outbreak of World War Two, it took up its station and bagan flying patrols over the western approaches to the English Channel. For the next two years it was based at St. Eval which it occupied in an unfinished state in October 1939. In May 1940 No.217 began to receive Beauforts but teething troubles prevented these from being used operationally until 25 September and the Ansons did not end their patrols until December. The Beauforts concentrated on attacks on enemy shipping and minelaying until transferred to Ceylon in May. The aircraft flew out via Gibraltar and Malta where they spent two months attacking enemy shipping in the Mediterranean.

The ground echelon arrived in Ceylon in August where it received Hudsons for anti-submarine patrols, the Beauforts having been retained in the Middle East. New Beauforts began to arrive in April 1943, and by July the squadron had reverted to a strike unit, re-equipping with Beaufighters in July 1944. The Japanese made no further attempts to attack Ceylon and No. 217 spent its time defensively until May 1945, when it was posted to Cocos Island to prepare for invasion in Malaya. This was forestalled by the Japanese surrender and the squadrons aircraft never did get to Coco's but moved from Vavuniya in Ceylon to Gannavram in Southern India in June 945 where it stayed until disbanded on 30 September 1945.

On 14 January 1952, No. 217 reformed at St. Eval as a maritime reconnaissance squadron and received two Neptunes for trials. In April it moved to Kinloss where it equipped fully in July 1952, flying Neptunes until disbanded on 31 March 1957. On 1 February 1958, the squadron reformed from No. 1360 Flight with Whirlwinds and moved to Christmas Island as part of a combined force of Shackeltons, Canberras and Whirlwinds supporting the Nuclear trials being carried out there. On 13 November 1959, the squadron disbanded.