Thomas Cullity was born in Port Adelaide in 1925, the son of timber merchant Thomas Cullity and Margaret Anglin. He graduated from Adelaide University in 1947, and began his career as a cardiologist.
He had a long association with the Royal Perth Hospital and was Consulting Cardiologist to the Sir Charles Gairdner and Fremantle Hospitals, as well as the Royal Perth Hospital. He also founded Vasse Felix vineyard in 1967, the first vineyard established in the Margaret River wine region. He retired in 1983 and died on the 22nd of July 2008.