San Marino at the 2020 Summer Olympics

San Marino participated at the 2020 Summer Olympics in Tokyo, Japan, held between 23 July and 8 August 2021. It was originally scheduled to take place from 24 July to 9 August 2020, but was postponed because of the COVID-19 pandemic. The country's participation in the Games marked its fifteenth appearance at the Summer Olympics since its debut in the 1960 Games.

The San Marino team consisted of five athletes who competed across four sports. Swimmer Arianna Valloni and wrestler Myles Amine served as the country's flag-bearer during the parade of nations in the opening ceremony, and Amine served as the flag-bearer during the closing ceremony.

San Marino had not won a Summer Olympics medal before the Games. The nation's first Olympic medal, a bronze medal, was won by female trap shooter Alessandra Perilli. With this San Marino became the smallest country, by population, ever to have won any Olympic medal. Two days later, on 31 July, Perilli and Gian Marco Berti won the country's second medal, a silver in the mixed trap shooting event. San Marino then took home its third medal on 5 August, with Amine winning a bronze in the 86 kg freestyle wrestling event. San Marino was ranked 72nd in the medal table, and with five competitors, the nation had the most overall medals per population.