At 19 years 286 days, Landeskog is 11 days younger than Sidney Crosby was when he was given the "C" by the Pittsburgh Penguins in 2007.
Landeskog was the second overall pick in the 2011 draft and won the Calder Trophy as rookie of the year last season.
He had 18 goals and 52 points for the Avs while playing all 82 games. The teenager finished with a plus-20 rating.
Landeskog takes over the captaincy from Milan Hejduk, who recently informed coach Joe Sacco that he wanted to relinquish the role.