MRCS LRCP 1943; MB ChB Manch 1943, MD 1946; MRCGP 1954.
Fletcher studied at the University of Manchester and was Sybil M. Pilkington Research Fellow at the University. Fletcher was later medical officer in charge of the EMS Hospital in Weaverham, Cheshire and resident medical officer at Warrington General Hospital before being appointed clinical assistant to the department of haematology at Withington Hospital Manchester and chief medical assistant (department of clinical investigations and research) at the University of Manchester and MRI. Fletcher was a general practitioner in Handforth, Cheshire, and was a member of Manchester Medical Society .