Landeskog -- winner of the NHL's Calder Trophy as rookie of the year last season -- was named captain after veteran Milan Hejduk told the Avalanche coaching staff he'd be relinquishing the role, the team said.
Hejduk and Paul Statsny will serve as alternate captains.
The Avalanche said that at 19 years, 286 days, Landeskog is the youngest captain in NHL history -- 11 days younger than when a 19-year old Sidney Crosby named captain of the Pittsburgh Penguins May 31, 2007.
The Swedish teen was Colorado's second-overall pick in the 2011 NHL Draft. He finished tied for first among rookies with 52 points (22 goals, 30 assists) while appearing in all 82 Avalanche games last season.