Lucas Pezzini Leiva (born 9 January 1987), known as Lucas, is a Brazilian professional footballer who plays as a defensive midfielder for English club Liverpool.

Lucas began his career as a box-to-box midfielder at Grêmio where he won the Campeonato Gaúcho in 2006 and 2007. In July 2007 he moved to Liverpool, where he developed into one of the league's premier defensive midfielders. Lucas has since made over 300 appearances for the club and won the League Cup in 2012. Between 2010 and 2016 Lucas led the Premier League in tackles per game five times in six seasons.