OL 2020 - Herredouble

Croatia's Nikola Mektić and Mate Pavić defeated compatriots Marin Čilić and Ivan Dodig in the final, 6–4, 3–6, [10–6] to win the gold medal in Men's Doubles tennis at the 2020 Summer Olympics. This was Croatia's first Olympic tennis gold and silver medals. For the first time since 1908, the gold medal match was contested by pairs representing the same country. In the bronze medal match, New Zealand's Marcus Daniell and Michael Venus defeated the United States' Austin Krajicek and Tennys Sandgren, 7–6^(7–3), 6–2. It was New Zealand's first Olympic tennis medal.

Spain's Marc López and Rafael Nadal were the reigning gold medalists from 2016, but they chose not to participate.

This was the 16th (medal) appearance of the men's doubles tennis event. The event has been held at every Summer Olympics where tennis has been on the program: from 1896 to 1924 and then from 1988 to the current program. A demonstration event was held in 1968.

The competition was a single-elimination tournament with a bronze medal match. Matches were best-of-3 sets, except that the third set was a match tiebreak (first to 10 points) instead of a typical set. A tiebreak was played if one of the first two sets reached 6–6.