Ivan Lendl (born March 7, 1960) is a former World No. 1 professional tennis player. Originally from Czechoslovakia, Lendl became a United States citizen. He was one of the game's most dominant players in the 1980s and remained a top competitor into the early 1990s.

He is considered to be one of the greatest tennis players of all time.Lendl captured eight Grand Slam singles titles. He competed in 19 Grand Slam singles finals, at the time a record for a man since surpassed by Roger Federer in 2009.

He reached at least one Grand Slam final for 11 consecutive years, a record shared with Pete Sampras. Before the formation of the ATP Lendl reached a record 12 year end championships (equaled by John McEnroe).

He won 2 WCT Finals titles and a record 5 Masters Grand Prix titles,tied with Pete Sampras and Roger Federer. He also won a record 22 Championship Series titles (1980–89) the precursors to the current ATP Masters 1000. Lendl first attained the World No. 1 ranking on February 28, 1983 and bolstered his claim to the top spot when he defeated John McEnroe in the 1984 French Open final.

For much of the next five years, Lendl was the top ranked player until August 1990 (with a break from September 1988 to January 1989 when Mats Wilander was at the top).

He finished four years ranked as the world's top player (1985–1987 and 1989) and was ranked No. 1 for a total of 270 weeks and set a new record previously held by Jimmy Connors since broken by Pete Sampras and Roger Federer.

Lendl's game relied particularly on strength and heavy topspin from the baseline and helped usher in the modern era of "power tennis". He himself called his game as "hitting hot", a relentless all-court game that was coming to dominate in tennis.