2019 French Open – Men's singles

Two-time defending champion Rafael Nadal defeated Dominic Thiem in a rematch of the previous year's final, 6–3, 5–7, 6–1, 6–1 to win the men's singles tennis title at the 2019 French Open. It was his record-extending twelfth French Open title and 18th major title overall. With the win, Nadal surpassed Margaret Court's all-time record for the most singles titles by a player at the same major.

Novak Djokovic and Roger Federer were both attempting to complete double career Grand Slam, with Djokovic also in contention to achieve a non-calendar-year Grand Slam, but both lost in the semifinals. This was Federer's first time playing the French Open in four years. Federer's third round match marked his 400th major match, an all-time record. Federer was the oldest man to reach the fourth round at the French Open since Nicola Pietrangeli in 1972, and the oldest semifinalist since the 40-year-old Pancho Gonzales in 1968.

The first round match between Ivo Karlović (40 years and three months) and Feliciano López (37 years and 8 months) was the oldest French Open men's singles match in terms of combined ages in the Open Era. Karlović was the oldest man to compete in the singles tournament since István Gulyás in 1973. Stefanos Tsitsipas was the first Greek to reach the round of 16 since Lazaros Stalios in 1936.

For only the third time in the Open Era and the first time since the 1970 Australian Open, all of the top 10 seeds reached the round of 16 at a men's singles major. It was the first time since the 2013 Australian Open that the top four seeds (Djokovic, Nadal, Federer, and Thiem) all reached the semifinals of a major, and the first time since the 2012 French Open that the Big Three all reached the semifinals of a major.

This marked the final major appearance of 2009 US Open champion Juan Martín del Potro, who lost to Karen Khachanov in the fourth round. Del Potro would retire from tennis in 2022 due to recurring injuries.