Ligety opened a huge lead after the first of two runs and then made a conservative trip down the course in the second run to finish in front of two Frenchmen. It was the first alpine gold medal of the Sochi Olympics for the Americans.
Steve Missillier took the silver and the bronze went to Alexis Pinturault.
Ligety won the combined race at the Turin Olympics eight years ago, but was shut out of the medals in Vancouver. He won the giant slalom, super-G and combined at last year's world championships in Austria.