| William R. Cornish | |
| Birth Date: | 2 March 1890 |
| Death Place: | Alberta, Canada |
| Birth Place: | Kingsbridge, Devon, England, United Kingdom |
| Office: | Member of the Legislative Assembly of Alberta |
| Constituency: | Vermilion |
| Term Start: | 1944 |
| Term End: | 1955 |
| Predecessor: | William Fallow |
| Successor: | Russell Whitson |
| Party: | Social Credit |
William Rich Cornish (March 2, 1890 - December 29, 1969) was a provincial politician from Alberta, Canada. He served as a member of the Legislative Assembly of Alberta from 1944 to 1955, sitting with the Social Credit caucus in government.[1]