Worley turned in two solid runs for a combined time of 2 minutes, 8.06 seconds, a comfortable 1.12 seconds faster than runner-up Tina Maze of Slovenia.
"It was hard today," said Worley. "It was a very tough course and I had to concentrate on myself only, letting my skis go and not do too many mistakes."
Austria's Anna Fenniger took the bronze in 2:09.24. Mikaela Shiffrin was the top U.S. finisher with a sixth-place time of 2:10.36.
Worley gave France its fourth medal of the worlds and first place in the event's medal standings.
Maze, the defending world champ in the giant slalom, maintained her wide lead in the World Cup overall points standings followed Maria Hoefl-Riesch of Germany, who finished ninth in Thursday's race.