McDavid, who led the NHL with 108 points this season, helped Canada win gold at the 2016 tournament.
"We have a mix of youth and veterans on our team, and the three players chosen to wear a letter know what it takes to be successful in international competition and that will help us be successful in our ultimate goal," Canada head coach Bill Peters said Monday in a release.
Hockey Canada also announced Monday that Colorado forward Tyson Jost has been added to the roster. Jost had 12 goals and 10 assists in 65 games in his NHL rookie season.
Canada is staging its pre-tournament camp in Riga and will play the Latvian national team in a pre-tournament game Tuesday.
Sweden is the defending champion at this year’s competition. Canada settled for silver last year after taking gold in 2015 and 2016.
Canada will open the tournament Friday against the United States.