A lifelong citizen of Toronto, William James Stewart devoted most of his life to public service. He served as alderman, 1924-30, and as mayor 1931-34. During his tenure as mayor he was instrumental in restoring Fort York to commemorate the city's centennial in 1934.
Elected to the Ontario Legislature in 1938, he served until 1959, and for four years was Speaker of the Legislative Assembly. A strong supporter of the militia, he joined the Queen's York Rangers (1st American Regiment) and was for fifteen years its honorary colonel.
He was active in numerous church, fraternal and charitable organizations, and served as chairman of the Toronto Historical Board from 1961 until his death.