| William N. Sweeney | |
| State: | Kentucky |
| District: | 2nd |
| Term Start: | March 4, 1869 |
| Term End: | March 3, 1871 |
| Predecessor: | Burwell C. Ritter |
| Successor: | Henry D. McHenry |
| Birth Date: | 5 May 1832 |
| Birth Place: | Liberty, Kentucky |
| Death Place: | Owensboro, Kentucky |
| Restingplace: | Elmwood Cemetery |
| Party: | Democrat |
| Alma Mater: | Bethany College |
| Profession: | Lawyer |
William Northcut Sweeney (May 5, 1832 – April 21, 1895) was a U.S. Representative from Kentucky.
Born in Liberty, Kentucky, Sweeney attended the common schools and Bethany College.He studied law.He was admitted to the bar in 1853 and commenced practice in Liberty, Kentucky.He moved to Owensboro, Daviess County, in 1853.He served as prosecuting attorney of Daviess County 1854–1858.He served as presidential elector on the Democratic ticket of Douglas and Johnson in 1860.
Sweeney was elected as a Democrat to the Forty-first Congress (March 4, 1869 – March 3, 1871).He was renominated in 1870, but declined to accept the nomination.He resumed the practice of law in Owensboro, Kentucky, and died there April 21, 1895.He was interred in Rosehill Elmwood Cemetery.