No. 91 Group RAF is a former Royal Air Force group. The group was formed on 11 May 1942 at Abingdon as No. 91 (Operational Training) Group RAF in RAF Bomber Command, it was previously No. 6 Group RAF. On 14 April 1947 it moved to Morton Hall, Swinderby and was amalgamated with and renamed No. 21 Group RAF on 1 May 1947.