It varies greatly from province to province. Some like Manitoba and Quebec are almost all hydro electric.. This however is the breakdown for Ontario in 2018.
Nuclear energy: 58.8%
Water power: 23.9%
Wind: 8%
Natural gas: 7%
Solar: 1%
Bioenergy: 1%
Other: 0.3%
Being near Columbia Generating Station (nuclear) here in WA State, I’ve known engineers who transferred between the plants. Hydro dams here also, of course.