| Simon S. Cook | |
| Office1: | Ontario MPP |
| Term Start1: | 1867 |
| Term End1: | 1874 |
| Predecessor1: | Riding established |
| Successor1: | Andrew Broder |
| Constituency1: | Dundas |
| Party: | Liberal |
| Birth Date: | 15 September 1831 |
| Birth Place: | Williamsburgh, Dundas County, Upper Canada |
| Death Place: | Merchant |
| Relations: | James William, brother Hermon Henry, brother |
Simon Sephrenus Cook (September 15, 1831 – May 15, 1892) represented Dundas in the Legislative Assembly of Ontario as a Liberal member from 1867 to 1874.
He was born in Williamsburgh in Dundas County in Upper Canada in 1831 and educated at the Potsdam Academy in Potsdam, New York. He lived in Morrisburg and was involved in the timber trade. In 1881, he was appointed registrar for the county. His brother James William represented Dundas in the Legislative Assembly of the Province of Canada and his brother Hermon Henry served in both the federal and provincial legislatures.