BSC Lond 1885, MB BS 1890, MD 1892; MB ChB Manch 1889; MRCS Eng 1889.
McGowan studied medicine at Owens College Manchester. He was house surgeon at MRI before moving to Oldham where he was honorary surgeon to Oldham Infirmary and district medical officer to Oldham Union. His sons, Alan Sinclair McGowan and Graham Kemp McGowan, and his daughter Kathleen, also practised medicine (see above and below). McGowan died on 24 July 1948 in his eighty-second year.