League disciplinarian Brendan Shanahan ruled Kaleta's hit to be illegal after holding a hearing with the player and reviewing the hit, which occurred five minutes into a 3-2 loss to the Philadelphia Flyers on Wednesday night.
Kaleta was battling for the puck along the boards in the Sabres' zone, when he lunged head-first into a crowd of players with the crown of his helmet, striking Philadelphia's Jakub Voracek in the chest and face.
Shanahan, who has taken a hard stance against head hits in his first year on the job, noted in a video announcing the suspension on NHL.com that this is the third such incident involving Kaleta in less than two years.
Kaleta will lose $19,621.64 in salary while serving the suspension, which starts with Buffalo's home game Friday against Calgary.
To fill Kaleta's spot, the Sabres promoted forward Corey Tropp from their American Hockey League affiliate in Rochester.
Tropp has never played an NHL game and has four goals and three assists in 10 games for Rochester this season.