William Machin Stairs, (January 21, 1789 – November 28, 1865) was a merchant, a banker, and a statesman. He was born and died in Halifax, Nova Scotia, Canada. William Machin Stairs was the son of John Stairs (1749–1797), a native of Grenada who had emigrated to Philadelphia, Pennsylvania, United States before moving to Halifax. John Stairs became involved in the shipping business but after some financial difficulties the family returned to Philadelphia in 1793. There, both John Stairs and his wife died and their five children, including the eight-year-old William Machin Stairs, returned to Halifax to be raised by a maternal uncle.