Vonn, the first American woman to win the Olympic downhill, edged out German Maria Riesch, a double gold winner in Vancouver, for the overall title at the World Cup finals in Garmisch-Partenkirchen, Germany.
Vonn had already clinched the overall title when Riesch, who needed to finish in the top two of the super giant slalom to stay in points contention, was knocked into third place before Vonn ran.
Just for good measure, though, the 25-year-old Vonn won the super-G race to record her American-record 33rd World Cup victory, one more than teammate Bode Miller.
"I knew what place Maria was in, so I knew the World Cup overall was already secured," Vonn said. "But I still wanted to go out there and have a good end to the season, I'm just really happy I had a good run and was able to end the season well."
American Ted Ligety, who failed to medal at the Olympics, clinched his second World Cup giant slalom event title with a third-place finish on Friday.