| William Dynes | |
| Office1: | Ontario MPP |
| Term Start1: | 1894 |
| Term End1: | 1898 |
| Predecessor1: | John Barr |
| Successor1: | John Barr |
| Constituency1: | Dufferin |
| Party: | Patrons of Industry |
| Birth Date: | 1849 |
| Birth Place: | Mono Township, Canada West |
| Death Place: | Victoria, British Columbia |
| Occupation: | Farmer |
William Dynes (1849 - 1935) was an Ontario farmer and political figure. He represented Dufferin in the Legislative Assembly of Ontario from 1894 to 1898 as a Patrons of Industry member.
He was born in Mono Township. Dynes served as reeve for Mono and was the first postmaster for Granger. He was also president of the Dufferin Mutual Fire Insurance Company. He defeated the incumbent, Doctor John Barr, to win a seat in the provincial assembly in 1894 but was defeated by Barr in 1898. In 1906, he moved to Saskatchewan. Dynes died in Victoria, British Columbia.