Crosby became available after the New York Rangers beat Pittsburgh in five games in their first-round NHL playoff series.
"Any time you can represent Canada, it's an honour," Crosby said. "I looked at the roster Hockey Canada has put together and I'm excited about the opportunity we have to win gold."
The native of Cole Harbour, N.S., led the Penguins with 84 points (28 goals, 56 assists) in 77 games this season.
He added two goals and two assists in five playoff games.
The Penguins forward has played for 10 seasons in the NHL, scoring 302 goals and adding 551 assists in 627 games.
He won the Hart Trophy as the NHL's most valuable player in 2007 and 2014 and led the Penguins to the 2009 Stanley Cup title.
Crosby has represented Canada six other times over his career, most notably at the 2010 Vancouver Olympics.
Crosby served as team captain in Vancouver and scored the game-winning goal against the U.S. in the gold-medal final.
He played for Canada at the 2006 world championship in Latvia, scoring a tournament-high 16 points as Canada finished fourth.
With the addition of Crosby, Canada's roster now stands at 21 players: two goaltenders, five defenceman and 14 forwards.
Former San Jose coach Todd McLellan will lead a young team that also includes forwards Taylor Hall, Tyler Seguin, Claude Giroux and Nathan MacKinnon and defenceman Aaron Ekblad.