Jacob Muzzin (born February 21, 1989) is a former Canadian professional ice hockey defenceman and works in Player Development for the Toronto Maple Leafs.

He previously had played 12 seasons in the National Hockey League (NHL) for the Los Angeles Kings and Toronto Maple Leafs.

There he served as team captain and won the Max Kaminsky Trophy as the top defenceman in the OHL.

After a spinal injury suffered in 2022 resulted in his placement on long-term injured reserve, Muzzin joined the Maple Leafs' front office as a professional scout in 2023.

[5] Muzzin signed as a free agent to a three-year, entry-level contract with the Los Angeles Kings on January 4, 2010.

[7] However, on November 3, 2010, he was assigned to the Kings' American Hockey League (AHL) affiliate, the Manchester Monarchs.

[14] At the beginning of the 2013–14 season, Muzzin began as a third line pairing and was a healthy scratch for a series of games.

[18] During the 2018 playoffs, due to an upper-body injury, Muzzin played in only two games in a 4–0 series loss to the Vegas Golden Knights.

[19] On January 28, 2019, with the Kings one point from last place in the league standings, Muzzin was traded to the Toronto Maple Leafs in exchange for forward Carl Grundström, the playing rights to Sean Durzi, and Toronto's first-round pick in the 2019 NHL Entry Draft.

[28] Muzzin remained on injured reserve to start the 2023–24 season, with new Maple Leafs general manager Brad Treliving confirming in late September 2023 that Muzzin would miss the entire season due to his spinal injury suffered the prior year.

[29][30] Despite not officially retiring, Muzzin later joined the Maple Leafs' front office in early October as a professional scout.