Canada as most people know borders the United States; It’s the longest land border between two countries on the planet in fact.
However contrary to common belief, the USA is not the only country that Canada borders.

For those unfamiliar with Canada’s geography, there is a territory in the far north called Nunavut – which is Canada’s largest ‘division’.
Rather close to Nunavut’s northern reaches is the Danish territory of Greenland.

Prior to 2022, there was a small island called Hans Island halfway between Ellesmere Island in Nunavut and mainland Greenland which was disputed between Canada and Denmark. The two countries had a friendly clash where for years they would take down the other’s flag, replace it with theirs, and provide a bottle of liquor from their respective country.

In June of 2022, the two countries symbolically came to an agreement to split the island in half, forming both Canada and Denmark’s second land border; Canada previously only shared one with the USA and Denmark with Germany.

Long story short, Canada’s only other land border aside from the USA is with Denmark.
A marine border with France, rather the French territory of St. Pierre and Miquelon, does exist off the coast of Newfoundland – However I don’t think this question was asking about marine borders (aforementioned Greenland also has a marine border with Canada).
However all types of borders included, France, Denmark, and the USA would make up Canada’s neighbours.

I’ve been getting a few comments about Canada’s border with France (St. Pierre and Miquelon). This is in fact a border, but a marine border as I mentioned, not a land border. Canada and St. Pierre and Miquelon do not physically touch.

The photo above is of the aforementioned Hans Island.