| Willard C. O'Brien | |
| Birth Date: | 15 December 1893 |
| Birth Place: | Noel, Nova Scotia |
| Death Place: | Yarmouth, Nova Scotia |
| Office: | MLA for Yarmouth County |
| Term Start: | October 30, 1956 |
| Term End: | October 8, 1963 |
| Predecessor: | William H. Brown Raymond Z. Bourque |
| Successor: | George A. Snow |
| Party: | Liberal |
| Spouse: | Marguerite Murphy |
| Occupation: | physician, politician |
Willard Cleveland O'Brien (December 15, 1893 – November 6, 1981) was a physician and political figure in Nova Scotia, Canada.
Born in Noel, Nova Scotia, he graduated from Dalhousie Medical School in 1919.
He served as the mayor of Wedgeport, Nova Scotia from 1936 to 1942 and he represented Yarmouth County in the Nova Scotia House of Assembly from 1956 to 1963 as a Liberal member. He ran for reelection in 1963 but lost by 165 votes to George A. Burridge.
He was married to Marguerite (Murphy), sister of Walter Murphy, who served as the last mayor of Wedgeport.[1]