| William Allen Walsh | |
| Birthname: | William Allen Walsh |
| Birth Date: | 1887 8, df=yes |
| Birth Place: | Kingston, Ontario, Canada |
| Spouse: | Edith Thompson m. 27 December 1916[1] |
| Riding: | Mount Royal |
| Predecessor: | Robert Smeaton White |
| Successor: | Fred Whitman |
| Term Start: | October 1935 |
| Term End: | March 1940 |
| Profession: | school principal, school superintendent, teacher |
| Party: | Conservative |
William Allen Walsh (20 August 1887 – 18 October 1940) was a Conservative member of the House of Commons of Canada. He was born in Kingston, Ontario and became a school principal, school superintendent and teacher, primarily at the Protestant Strathcona Academy in the Montreal suburb of Outremont.
He was first elected to Parliament at the Mount Royal riding in the 1935 general election. After serving one term, the 18th Canadian Parliament, Walsh entered the March 1940 election under the Conservative-based National Government party banner but was defeated by Fred Whitman of the Liberal party. Walsh died months later, on 18 October 1940.
Walsh remains the last member of the House of Commons of Canada to represent the Mount Royal riding who was not a Liberal.