| Honorific-Prefix: | The Hon. |
| Frederick William Gershaw | |
| Birth Date: | 1883 4, df=yes |
| Birth Place: | Emerson, Manitoba, Canada |
| Riding: | Medicine Hat |
| Predecessor: | Robert Gardiner |
| Successor: | Archibald Hugh Mitchell |
| Term Start: | 1925 |
| Term End: | 1935 |
| Predecessor2: | Archibald Hugh Mitchell |
| Successor2: | William Duncan Wylie |
| Term Start2: | 1940 |
| Term End2: | 1945 |
| Office3: | Senator for Medicine Hat |
| Term Start3: | 1945 |
| Term End3: | 1968 |
| Appointed3: | William Lyon Mackenzie King |
| Party: | Liberal |
| Nationality: | Canadian |
Frederick William Gershaw (11 April 1883 - 26 June 1968) was a Canadian physician and politician.
Born in Emerson, Manitoba, he received a Doctor of Medicine from the University of Manitoba in 1911. He became a medical officer for the Canadian Pacific Railway and moved to Medicine Hat, Alberta. In 1912, he married Harriet Robinson, a registered nurse. They had 4 daughters: Margaret, Edith, Norma, and Lorraine.
He first ran unsuccessfully for the House of Commons of Canada in the riding of Medicine Hat in the 1921 federal election. A Liberal, he was elected in the 1925 federal election and re-elected in 1926 and 1930. He was defeated in 1935 and was re-elected in 1940. He was appointed to the Senate of Canada in 1945 representing the senatorial division of Medicine Hat. He resigned in 1968 shortly before his death.
Senator Gershaw School in Bow Island, Alberta is named in his honour, in addition to Gershaw Drive Southwest in Medicine Hat – an urban limited-access road carrying portions of Highway 41A and Highway 3.