In 2011-12, he scored 73 points (32 goals, 41 assists) in 66 games with Sudbury before playing one game for Toronto of the American Hockey League. The following season, he scored a combined 73 points (29 goals, 44 assists) in 63 games with Sudbury and Kitchener of the OHL and played four AHL games, getting two assists.

Leivo was selected by the Toronto Maple Leafs in the third round (No. 86) of the 2011 NHL Draft after he scored 30 points (13 goals, 17 assists) in 64 games for Sudbury of the Ontario Hockey League.

Leivo was selected by the Toronto Maple Leafs in the third round (No. 86) of the 2011 NHL Draft after he scored 30 points (13 goals, 17 assists) in 64 games for Sudbury of the Ontario Hockey League.

In 2011-12, he scored 73 points (32 goals, 41 assists) in 66 games with Sudbury before playing one game for Toronto of the American Hockey League. The following season, he scored a combined 73 points (29 goals, 44 assists) in 63 games with Sudbury and Kitchener of the OHL and played four AHL games, getting two assists.

On March 5, 2013, the Maple Leafs signed Leivo to a three-year, entry-level contract. He made his NHL debut against the Nashville Predators on Oct. 10, 2013 and scored his first NHL goal in a 3-2 loss to the Carolina Hurricanes one week later. He scored two points (one goal, one assist) in seven games before he was sent to the AHL on Oct. 26. He scored 42 points (23 goals, 19 assists) in 59 games.

Leivo played most of the 2014-15 season with Toronto of the AHL, where he scored 32 points (11 goals, 21 assists) in 51 games. He played nine games for the Maple Leafs, scoring one goal.

Named to the 2016 AHL All-Star Classic, Leivo finished the season with 48 points (17 goals, 31 assists) in 51 games and led Toronto forwards with 12 points (four goals, eight assists) in 15 games of the Calder Cup Playoffs. He also played in 12 games with the Maple Leafs and scored five goals.

Leivo signed a two-year contract with the Maple Leafs on July 21, 2016. He was traded to the Vancouver Canucks on Dec. 3, 2018.

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