Lleyton Glynn Hewitt AM (/ˈleɪtən ˈhjuːᵻt/; born 24 February 1981) is an Australian former world no. 1 professional tennis player.
In November 2001 Hewitt became the youngest male ever to be ranked no. 1 in the world in singles, aged 20. He won the 2001 US Open and 2002 Wimbledon men's singles titles, the 2000 US Open men's doubles title, back-to-back Tennis Masters Cup titles in 2001 and 2002, and the Davis Cup with Australia in 1999 and 2003. Hewitt reached the final of the 2004 US Open, where he was defeated by Roger Federer in straight sets. Between 1997 and 2016, he contested twenty consecutive Australian Open men's singles tournaments, reaching the 2005 final where he was defeated by Marat Safin in four sets.
He concluded his professional tennis career at Wimbledon 2016 in the Gentlemen's doubles competition, where he played alongside countryman Jordan Thompson and lost to eighth seeds Vasek Pospisil and Jack Sock in the second round.