| Band Name: | Thessalon First Nation |
| Band Number: | 202 |
| People: | Ojibwe |
| Treaty: | Robinson Huron & Pennefather |
| Headquarters: | 40 Sugarbush Road, Thessalon |
| Province: | Ontario |
| Main Reserve: | Thessalon 12 |
| Area: | 9.42 |
| Pop Year: | 2024 |
| On Reserve: | 113 |
| On Other Land: | 4 |
| Off Reserve: | 1116 |
| Total Pop: | 1233 |
| Chief: | Joseph Wabigwan |
| Council: | Lisa Boulrice Roxanne Boulrice Mary Anne Giguere Robert H. Simon Robert S. Simon |
| Tribal Council: | Anishinabek Nation Mamaweswen, The North Shore Tribal Council |
| Website: | https://www.thessalonfirstnation.ca/ |
| Footnotes: | [1] |
| Thessalon 12 | |
| Official Name: | Thessalon Indian Reserve No. 12 |
| Settlement Type: | Indian reserve |
| Pushpin Map: | Canada Ontario |
| Pushpin Mapsize: | 200 |
| Coordinates: | 46.25°N -108°W |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Type2: | District |
| Subdivision Name2: | Algoma |
| Subdivision Type3: | First Nation |
| Subdivision Name3: | Thessalon |
| Area Land Km2: | 9.79 |
| Population Footnotes: | [2] |
| Population Total: | 108 |
| Population As Of: | 2011 |
| Population Density Km2: | 11.0 |
| Timezone: | EST |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
Thessalon First Nation is an Ojibwe First Nation in Algoma District, Ontario. Their reserve is located at Thessalon 12. They are a member of the Anishinabek Nation.
The traditional territory of Thessalon First Nation was established through extensive use and mutual recognition between Anishinaabe and communities of the area. This was recognized in the Vidal-Anderson Commission report of 1849. Thessalon First Nation's right to use the territory was recognized much earlier by the Crown in the Royal Proclamation of 1763, and in the Treaty of Niagara in 1764. The traditional territory reserved by Thessalon First Nation in the Lake Huron Treaty of 1850.