Vonn, one of the greatest World Cup skiers of all time, left the sport in 2019 after a series of major injuries but she has been free of pain since a right knee replacement in April.
The 82-time World Cup race winner, took part in the 'FIS Fall Festival', a second tier event, at Copper Mountain in Colorado and went down twice in Saturday's downhill sessions.
The American finished 24th in a field of 43, 1.44sec behind Austrian winner Mirjam Puchner.
Vonn has said she is using this week's event, which features several other races, as a "training opportunity" as she looks to re-enter the World Cup circuit.
It was a low key event but there was a small crowd gathered to watch her return and a smattering of applause for her at the finish area.
FIS, the international ski federation, said Vonn had requested a "wild card" entry to compete in two super-G races at St. Moritz on December 21 and 22, taking advantage of a new invitation system that allows former stars to return to the elite circuit after years away from competition and to have better starting positions.
Vonn was the most decorated women's skier with 82 World Cup victories when she retired. Her mark has since been eclipsed by fellow American Mikaela Shiffrin's 99.
She recorded her first World Cup victory in 2004 and won three Olympic medals - including downhill gold in 2010 in Vancouver.
Vonn also won 20 World Cup titles, including four overall crystal globes, eight world championship medals and secured 137 World Cup podiums.
The next Winter Olympics take place in Milan and Cortina d'Ampezzo in 2026.