| Champlain | |
| Official Name: | Township of Champlain Canton de Champlain |
| Settlement Type: | Township (lower-tier) |
| Flag Size: | 120x100px |
| Pushpin Map: | CAN ON Prescott and Russell#Canada Southern Ontario |
| Coordinates: | 45.5333°N -113°W |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Type2: | County |
| Subdivision Name2: | Prescott and Russell |
| Established Title: | Settled |
| Established Title2: | Formed |
| Established Date2: | January 1, 1998 |
| Leader Title: | Mayor |
| Leader Name: | Normand Riopel |
| Leader Title1: | Federal riding |
| Leader Name1: | Glengarry—Prescott—Russell |
| Area Land Km2: | 207.27 |
| Population Total: | 8,706 |
| Population As Of: | 2016 |
| Population Footnotes: | [1] |
| Population Density Km2: | 42.0 |
| Postal Code Type: | Postal Code FSA |
| Postal Code: | K0B |
| Area Code: | 613, 343 |
| Website: | www.champlain.ca |
| Leader Title2: | Prov. riding |
| Leader Name2: | Glengarry—Prescott—Russell |
| Timezone: | EST |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
Champlain is a township in eastern Ontario, Canada, in the United Counties of Prescott and Russell on the Ottawa River. It was formed on January 1, 1998, through the amalgamation of West Hawkesbury Township, Longueuil Township, Town of Vankleek Hill, and the Village of L'Orignal.
The township comprises the communities of Aberdeen, Cassburn, Green Lane, Happy Hollow, Henrys Corners, L'Ange-Gardien, L'Orignal, Pleasant Corners, Ritchance, Riviera Estate, Sandy Hill, Springhill, Vankleek Hill, Vankleek Hill Station, Village Lanthier, and St. Eugene. The township administrative offices are located in Vankleek Hill.
In the 2021 Census of Population conducted by Statistics Canada, Champlain had a population of living in of its total private dwellings, a change of from its 2016 population of . With a land area of 207.02km2, it had a population density of in 2021.[2]