(covers information from several alternate timelines)
Canada was a North American country on Earth that bordered the United States. The northernmost areas of this country were located in the Arctic Circle. Canada's national flag was red supporting a central white band with a red, eleven-pointed maple leaf. People or items which had their origin in this country were called Canadians. The languages of this country included English and French. (TOS-R: "The Cage"; TNG: "Lower Decks"; DS9: "Blaze of Glory"; ENT: "First Flight")
In the late 20th century, the Canadian Space Agency was founded in cooperation with NASA for the training of astronauts in the latter's space shuttle orbiter program. One of the first graduates of this program was Marc Garneau of STS-41G. (ENT: "First Flight")
A 21st century-era political map of Earth was stored in the USS Enterprise's library computer in 2254. The North American continent was seen on this map. This map was among the materials viewed by the Talosians when they scanned the Enterprise computer. (TOS-R: "The Cage")
Sam Lavelle's grandfather was Canadian, and he was mistakenly informed by Ben that William T. Riker was also from that country. In an attempt at small talk, Lavelle mentioned to Riker that his grandfather was from Canada, but when he asked Riker if he grew up there too, he stated that he was actually from Alaska. Lavelle was reduced to stating that both Canada and Alaska "get a lot of snow," which Riker conceded. (TNG: "Lower Decks")
Deep Space 9 briefly possessed a Starfleet runabout named the USS Yukon, named after the Yukon River which runs through the Yukon Territory and the US State of Alaska. (DS9: "Sons of Mogh", "By Inferno's Light") In 2375, this station had another runabout, the USS Gander, named after the Gander River in Newfoundland, site of an Allied Air force base from the early days of World War II. (DS9: "Penumbra")
The crew of the USS Voyager coined a corridor of Borg-free space the "Northwest Passage", which was named after the unmarked water "trail" for boats in the Arctic Ocean between islands of the Northwest Territories, used as the shortest route around the North American continent. (VOY: "Scorpion")
|Locations: Alberta • British Columbia • Calgary • Montreal • Victoria|
|People: Marc Garneau • Michael Eddington • William Lyon Mackenzie King • Sam Lavelle's grandfather • Sarah Paul Raymond • Julie Payette • Steven MacLean|
|Miscellaneous: Canadian Space Agency • Looney • Manitoba Journal of Interplanetary Psychology • Toronto City Hall • University of Manitoba|
Star Trek: Discovery is largely shot in Canada, particularly in and around Toronto, both in studios and on location. As a result, many of its cast members are Canadian (see Canadian for a list of Canadian Star Trek actors). Also, Star Trek Beyond was filmed in Vancouver.
During the 21st century, London, Ontario may have been the home of the professional baseball team, the London Kings, who were established in "The Big Goodbye" and "If Wishes Were Horses". It is equally likely the team could have been based out of London, England, United Kingdom.
"The Cage" maps
The maps used in the original "The Cage" were published in the early 1960s. It is probable that Canada was labeled on two 20th century-era political map of Earth used in the original "The Cage". However, due to the poor quality of the image and the inability to access the source material, this is far from certain.
Decades later, a Central Intelligence Agency map, which was used in the remastered "The Cage", was published either in April 2007  or September 2008 . The difference, which was not noticeable at the resolution of the image from the episode, was the addition of Kosovo, which gained its independence between the releases. The label "Canada" was not legible to the viewer.