LRCS LRFPS Glasgow, LM Edin 1889.
Sidley gained his medical education at Owens College and Edinburgh University. He was resident clinical assistant to Stockport Infirmary before being appointed surgeon to Eccles and Patricroft Hospital, at which he was later consultant surgeon. Sidley was also surgeon to St Joseph's Home for Children, Patricroft. Sidley died on 21 August 1939, aged 74. His son, Insall Martin Sidley (see below), was also a doctor.