Gustavo Alarcón (born 4 February 1999) is a Chilean foil fencer. In 2019, he won the silver medal in the men's foil event at the 2019 Pan American Games held in Lima, Peru. In the final, he lost against Gerek Meinhardt of the United States. In 2018, he competed in the men's foil event at the 2018 Pan American Fencing Championships held in Havana, Cuba without winning a medal. He was eliminated in his first match by Maximilien van Haaster of Canada.