LRCP LRCS Edinburgh, LRFPS Glasgow 1907; DPH Manch 1918.
Flack was born in Galway on 7 March 1882 and was educated at Galway, Belfast and Edinburgh. After a short time in Norwich, Flack went to practice in Radcliffe. He was a captain in the RAMC and in 1918 took the DPH at Manchester before serving for a year as specialist sanitary officer at the Cherbourg Base. He returned to general practice in Radcliffe where he pursued a distinguished public career, being Mayor of Radcliffe from 1938 until 1940. Flack was also a prominent member of the Labour Party. Flack died in Ireland on 22 May 1940.