Michael Grabner was born on October 5, 1987 in Villach, Austria. Following the move from his homeland of Austria to Canada, Grabner joined the Spokane Chiefs of the Western Hockey League and was selected 14th overall in the 2006 NHL Entry Draft by the Vancouver Canucks.
Grabner made his professional debut for the Canucks' AHL affiliate, the Manitoba Moose in 2007 and as a rookie produced 44 points in 74 games. Grabner got his first taste of NHL action during the 2009-10 season, appearing in 20 games for the Canucks and producing an impressive 11 points.
At the 2010 NHL Entry Draft, Grabner was traded to the Florida Panthers as part of a package that saw the Canucks acquire defenseman Keith Ballard.
Grabner's time in Florida would be short-lived however; he was waived by the club on October 3, 2010 and claimed by the New York Islanders.
In his first full season in the NHL, Grabner would lead all rookies in goal-scoring with 34 and his +13 rating was tied Islanders team best. For his efforts, Grabner received a nomination for the Calder Trophy as the league's top rookie. The award eventually go to Carolina forward Jeff Skinner.
After playing five seasons with the New York Islanders, Grabner was traded to the Toronto Maple Leafs for Taylor Beck, Carter Verhaeghe, Matt Finn, Tom Nilsson, and Christopher Gibson prior to the start of the 2015-16 season.