| Office: | Senator |
| Term Start: | 14 December 1961 |
| Term End: | 1 June 1973 |
| Constituency: | Nominated by the Taoiseach |
| Office1: | Teachta Dála |
| Term Start1: | June 1943 |
| Term End1: | October 1961 |
| Constituency1: | Donegal East |
| Party: | Independent |
| Otherparty: | Clann na Talmhan |
| Birth Date: | 18 January 1907 |
| Birth Place: | Derry, Ireland |
| Death Place: | County Donegal, Ireland |
| Alma Mater: | Queen's University Belfast |
| Education: | Foyle College |
William Alexander Watson Sheldon (18 January 1907 – 1 November 1999) was an Irish politician and farmer. From a protestant background, he was elected to Dáil Éireann at the 1943 general election as a Clann na Talmhan Teachta Dála (TD) for the Donegal East constituency.[1] He was re-elected as an independent TD at the 1944, 1948, 1951, 1954 and 1957 general elections.[2] He did not contest the 1961 general election.[3]
When tributes were paid to him in the Seanad after his death, it was said that this was because the constituency was reduced from 4 to 3 seats.[4] In 1961, he was nominated by the Taoiseach, Seán Lemass to the 10th Seanad. He was re-nominated to the Seanad in 1965 and 1969, and he retired from politics in 1973. He was also a member of Donegal County Council from 1945 to 1955.[4]