1999 French Open – Men's singles

Andre Agassi defeated Andrei Medvedev in the final, 1–6, 2–6, 6–4, 6–3, 6–4 to win the men's singles tennis title at the 1999 French Open. It was his first and only French Open title (following two runner-up finishes in 1990 and 1991) and fourth major title overall. Agassi became the second man in the Open Era (after Rod Laver) to complete the career Grand Slam and the first to do so across three surfaces. He also completed the career Golden Slam and the career Super Slam. Agassi was the third man in the Open Era to win a major singles final from two sets down, after Björn Borg at the 1974 French Open and Ivan Lendl at the 1984 French Open.

Carlos Moyá was the defending champion, but lost in the fourth round to Agassi.

This tournament marked the first major appearances for future 20-time major champion and world No. 1 Roger Federer and future champion Gastón Gaudio; they lost to Patrick Rafter and Àlex Corretja in the first round and third round, respectively. It was also the final major appearance for former world No. 1 and 1995 champion Thomas Muster, who was defeated by Nicolás Lapentti in the first round.