The Nation is a township in eastern Ontario, Canada, in the United Counties of Prescott and Russell on the South Nation River.
According to the 2001 Statistics Canada Census:
| North: Clarence-Rockland, Alfred and Plantagenet | ||
| West: Russell |
The Nation Casselman is completely surrounded by The Nation |
East: Champlain |
| South: North Stormont, North Glengarry |