Thomas Fuller was born in Bath, England where he trained as an architect. Living in Bath and London he did a number of projects. In 1845 he left for Antigua, where he spent two years working on a new cathedral before emigrating to Canada in 1857. Settling in Toronto, Ontario he formed a partnership with Chilion Jones with Fuller responsible for design work. In 1859 the firm won the competition to design the new Parliament Buildings in Ottawa and Fuller set to work creating the neo-gothic structure.
In 1867 he won the contract to build the New York State Capitol building in Albany, New York, and spent the next several years in the United States. In 1881 he returned to Canada to become Chief Dominion Architect, replacing Thomas Seaton Scott. He held this position until 1896, he played a role in the design and construction of every major federal building.