Which country borders Canada to the south?
- Greenland
- Mexico
- Russia
- The United States
Answer: The United States
The Canada–United States boundary runs along Canada’s southern edge. The other three sides face oceans: the Pacific to the west, the Atlantic to the east and the Arctic to the north. The two countries are each other’s largest trading partner.
Learn more: Size, borders and population
- Canada is the second largest country on earth, at about 10 million square kilometres.
- Three oceans: the Pacific Ocean to the west, the Atlantic Ocean to the east and the Arctic Ocean to the north.
- The Canada–United States boundary runs along Canada’s southern edge.
- Canada and the U.S.A. are committed to a safe, secure and efficient border.
- The border is traditionally known as “the world’s longest undefended border.” Millions of people cross it safely every year.
- Population: about 41.8 million people (July 2026 estimate).
- Most Canadians live in cities, but many live in small towns and rural areas.