Tennis at the 2016 Summer Olympics – Men's singles

Defending gold medalist Andy Murray of Great Britain defeated Juan Martín del Potro of Argentina in the final, 7–5, 4–6, 6–2, 7–5 to win the gold medal in men's singles tennis at the 2016 Summer Olympics. He became the first tennis player ever, male or female, to win two Olympic gold medals in singles. Murray and del Potro were only the third and fourth men to win multiple singles medals of any color (following del Potro's bronze in 2012). Murray's gold was Great Britain's fifth in men's singles, the most of any nation. In the bronze medal match, Japan's Kei Nishikori defeated Spain's Rafael Nadal, 6–2, 6–7, 6–3, earning Japan's first men's singles Olympic medal since 1920.

The tournament was held at the Olympic Tennis Centre in the Barra Olympic Park in Barra da Tijuca in the west zone of Rio de Janeiro, Brazil. The final was played on 14 August 2016. There were 64 players from 34 nations. Notably, this was the first Olympic tournament since the 1984 men's singles, not to feature any Swiss players.

World No. 1Novak Djokovic lost, in straight sets, to del Potro in the first round. Djokovic was attempting to complete the Career Golden Slam and Career Super Slam; his defeat marked his first loss in the opening round of a tournament since 2009. This was the second consecutive Olympic singles match where del Potro defeated Djokovic, following their encounter in the bronze medal match in 2012.