| Nelson William Trewartha | |
| Parliament: | Ontario Provincial |
| Term Start: | June 25, 1923 |
| Term End: | October 18, 1926 |
| Predecessor: | Andrew Hicks |
| Successor: | William George Medd |
| Riding: | Huron South |
| Party: | Conservative |
Nelson William Trewartha was a Canadian politician from the Conservative Party of Ontario. He represented Huron South in the Legislative Assembly of Ontario from 1923 to 1926.[1]