Ilie Năstase (born July 19, 1946, in Bucharest), former great Romanian professional lawn tennis player, the first World No. 1 ATP (1972-1973), known for his on-court histrionics and outstanding play. He was the first European to surpass $1 million in career prize money.

No player in history has been more gifted or mystifying than the Bucharest Buffoon, Ilie Năstase, noted both for his sorcery with the racket and his bizarre, even objectionable behavior. He was an entertainer second to none, amusing spectators with his antics and mimicry, also infuriating them with gaucheries and walkouts. Despite a fragile nervous system and erratic temperament, Năstase - a slender 6-footer quick, leggy and athletic - could do everything, and when his concentration held together he was an artist creating with great originality and panache. He was the first Romanian of international prominence, and largely through his play that small country rose to the Davis Cup final on three occasions, 1969, 1971, and 1972, losing each time to the U.S. At the end of 1985 after playing Davis Cup since 1966, 18 years, Năstase ranked second among the most active players in Cup history, having won 109 of 146 singles and doubles engagements in 52 ties. Though he provoked controversy and his career was marred by fines, disqualifications and suspensions, Năstase was good-natured and friendly off-court. He had a sense of humor in his on-court shenanigans, but frequently did not know when to stop and lost control of himself. "I am a little crazy, but I try to be a good boy", he said.

In terms of public popularity, Năstase was famous both for his technical and physical genius and for his good humour on court. But among referees and other players, his reputation for gamesmanship resulted in the nickname "Nasty" after several incidents where his temperament got the better of him.

In his career, Ilie Năstase won 7 Grand Slam finals (2 singles, 3 doubles, 2 mixed), 4 Masters Cup titles, 59 major tournaments, 28 minor tournaments, 51 double titles. In a career begun in the amateur era and continued in the open era, he is one of five players to win more than 100 pro titles in singles (59) and doubles (5l). After his retirement, in 1985, he became a businessman, but he still plays in demonstrative tournaments. He was inducted into the Tennis Hall of Fame in 1991. Maxim Magazine has placed Năstase at number 6 on its top ten "Living Sex Legends" list.