Adam Nicholas Barrett (born 29 November 1979) is an English former professional footballer who played as a central defender.

Born in Dagenham, Barrett began his career with Leyton Orient, but failed to make an appearance for them and moved on to sign for Plymouth Argyle, spending the 1999–2000 season with them.

He helped Southend from League Two to the Championship during a six-year stay at Roots Hall, and played over 250 times for the club before signing for Crystal Palace in 2010.

He scored 11 goals in his first season with the Blues, a high figure for a centre-back, and was voted Player of the Year by Southend fans.

[citation needed] Barrett was influential in Southend's sixth-place finish, though their season ended with a playoff semi-final defeat to Doncaster Rovers.

He played the full 90 minutes in a memorable 1–1 draw with Chelsea at Stamford Bridge in the FA Cup third round on 3 January 2009.

The newly appointed captain then netted his first competitive Cherries goal in his first home league match; a 2–0 win over Sheffield Wednesday on 13 August 2011.

An injury delayed Barrett's homecoming but he finally made his second debut for Southend as a second-half substitute against Cheltenham Town on 10 February 2015.