NBA Commissioner Adam Silver made the decision Saturday, a day after Cousins went down for the season with an Achilles tear. The All-Star Game is Feb. 18 in Los Angeles.
George was the next highest vote getter among frontcourt players in the West, both by the fan vote and when media/player votes were tallied and added in.
George is averaging 21.0 points, 5.5 rebounds, 3.0 assists and 2.17 steals in his first season with the Thunder after seven with Indiana.
Cousins was voted to start and drafted to Team LeBron by captain LeBron James. Cousins, having the best season of his career, ruptured his Achilles in the final seconds of the Pelicans win over the Rockets on Friday.