| State Senate: | New York |
| District: | 41st |
| Term Start: | 1905 |
| Term End: | 1906 |
| State Senate2: | New York |
| District2: | 43rd |
| Term Start2: | 1907 |
| Term End2: | 1908 |
| Birth Name: | William John Tully |
| Birth Date: | 1 October 1870 |
| Death Cause: | Heart attack |
| Resting Place: | Locust Valley Cemetery, Locust Valley, New York, U.S. |
| Children: | Three daughters |
| Profession: | Attorney, politician |
| Mawards: | is not set --> |
William John Tully (October 1, 1870 in Corning, Steuben County, New York – August 22, 1930) was an American lawyer and politician from New York.
He was the son of Joseph J. Tully and Sarah (Byers) Tully. He attended Corning Free Academy, Brooklyn Polytechnic Institute and Columbia College. He graduated LL.B. from New York Law School, was admitted to the bar, and practiced in Corning. On October 5, 1898, he married Clara Mabel Houghton (1870–1958), and they had three daughters, among them philanthropists Alice Tully (1902–1993) and Marion Tully Dimick (1904–1981).
Tully was a member of the New York State Senate from 1905 to 1908, sitting in the 128th, 129th (both 41st D.), 130th and 131st New York State Legislatures (both 43rd D.). Afterwards he was General Counsel of the Metropolitan Life Insurance Company in New York City. He was also active in the Episcopal Church, serving as president of the Deputies of the Synod in New York and New Jersey.
He died on August 22, 1930, while riding in an automobile from his home in Locust Valley, Nassau County, New York, to New York City; and was buried at the Locust Valley Cemetery.