Tennis has been around since the original modern Olympiad in 1896.
Laurie Doherty, the Federer of 1903-1906, won the Gold in 1900. Shame he and his bro Reggie Doherty didn't play, as they never did, just always gave a w/o to the other guy.
Max Decugis, 8 time French champ, was also in the 1900 draw, but didn't make it.
Beals Wright, 1905 US Champ, 1910 Wimbledon finalist, won the Gold in 1904. He also scored 3 doubles slams.
Josiah Ritchie won the Gold in the indoor 1908 event, he made the final of Wimbledon in 1909, and won Wimbledon doubes twice.
Arthur Gore won Wimbledon 3 times, as well as the gold in the outdoor 1908 event.
Andre Gobert won gold in 1912, as well as several slams in his time.
The war halted the momentum for 1920, but tennis rebounded in 1924 with a quality event.
Cochet def. Borotra in a tough all-French muskateer 4 setter in one SF, while Vinny Richards, who had taken out Lacoste in the QF in 5, beat the Italian Umberto de Morpurgo. Imagine the de Morpurgo-tards!!! Especially after he beat Borotra 7-5 in the 5th for the epic Bronze!
In the final, it was Cochet, a top 16 all time legend, vs. Vinny Richards. Richards won the match in 5 and won gold, then won gold also in the doubles. Richards won gold in 1924, and altogether won 7 doubles slams, 2 mixed doubles slams, and like 6 slam single SF.
Then the game lost momentum
44 years, 11 Olympiads without the event. Any sport would struggle. Even when it came back in 1968, the gold medal match was Santana def. Orantes, both slam champions. Then, there is no tennis again until 1984, another 3 missed Olympiads. And in 84, it was the great Edberg winning gold!
Miroslav Mecir, 2 time slam finalist, won gold in 1988, beating Edberg in 5 in the SF. Many people point to Marc Rosset winning gold in 1992 being muggy, but the guy beat Courier, Sanchez, and Ivanisevic en route. Agassi won gold in 96, his slam credentials are there, Kafelnikov won in 2000, he is a 2 time slam champ and former #1. Massu winning in 2004, ok, I'll give you, but then Nadal won in 08 to restore the prestige.
And this year, probably a former slam champ will win this.
So the sport has history of great champions winning gold.