Leon Peter Barnett (born 30 November 1985) is an English former professional footballer. A defender, he primarily played as a centre-back, but also played as a full-back, central midfielder and striker.
He began his career with Luton Town where he made his professional debut. After a brief loan spell with non-League side Aylesbury United, he established himself in the first team at Luton and made 70 appearances in all competitions before signing for West Bromwich Albion in 2007 for an initial fee of £2.5 million. In his first season with Albion, he helped the club win promotion to the Premier League by winning the 2007–08 Championship. He later lost his place in the side due to injury and loss of form, spending the majority of the 2009–10 season on loan with Coventry City.
He joined Norwich City on loan in 2010 before completing a permanent transfer in January 2011. His first season with Norwich led to a second career promotion from the Championship after finishing as runners-up. He appeared sporadically over the following two seasons and was loaned to Cardiff City in the final months of the 2012–13 season before being sold to Wigan Athletic at the end of the campaign. He made nearly 100 appearances for the club, winning League One during the 2015–16 season. He finished his career with spells at Bury and Northampton Town after being forced to retire at the age of 32 due to a heart condition.