William Moore Kelly (1827 – December 10, 1888) was a businessman and politician in New Brunswick.
He represented Northumberland County in the Legislative Assembly of New Brunswick from 1867 to 1878.
From 1869 to 1878, he served as commissioner of public works in the province's Executive Council.
He was heavily criticized later in his political career for accepting compensation in return for directing railway contracts to specific contractors.
In 1882, he resigned due to poor health and moved to Toronto, Ontario.