Port Arthur—Thunder Bay
| Ontario electoral district | |
|---|---|
| Defunct federal electoral district | |
| Legislature | House of Commons |
| District created | 1924 |
| District abolished | 1933 |
| First contested | 1925 |
| Last contested | 1930 |
Port Arthur—Thunder Bay was a federal electoral district represented in the House of Commons of Canada from 1925 to 1935. It was located in the province of Ontario. This riding was created in 1924 from parts of Algoma West and Port Arthur and Kenora ridings.
It consisted of the north-east parts of the territorial districts of Kenora and Thunder Bay.
The electoral district was abolished in 1933 when it was merged into Port Arthur riding.