The two-time reigning Olympic champion lost momentum after putting her hand in the snow and finished six hundredths of a second behind Austrian Sabine Payer, who ultimately took silver.
In 2018, in Pyeongchang, Ledecka became the first woman to win Olympic gold in two different disciplines. She won gold in the super-G and in the snowboard parallel giant slalom.
During this year's Winter Games, she will also compete in the super-G in Cortina.
Ledecka's miss gives Austria's Anna Gasser a chance to become the first snowboarder to win three straight Olympic gold medals. Gasser will take to the slopes in the big air qualifiers later Sunday.
