Thomas W. Mitchell was born in 1879 in Clarksburg, Ontario. It is believed he attended the Central Ontario School of Art for some time.
He lived in Toronto for most of his life, working for J. E. Laughlin, J.J. Gibbons, Bridgen's. He also worked as a freelance illustrator for several newspapers and magazines.
In 1944 he moved to Barrie where he taught at Barrie District Collegiate. He was a member of The Royal Canadian Academy of Arts.
He died in 1958.