William Thomas Braithwaite (14 April 1844 – 22 January 1918) was a Northern Irish businessman, freemason, and marksman. He was the co-founder of the public house chain of Braithwaite & McCann which eventually owned 15 bars and pubs in Belfast. In 1906 he made a large donation of paintings to the Belfast Municipal Museum and Art Gallery, now known as the Ulster Museum.