As a teenager, Barrett helped Chester City to promotion from Division Four in 1985-86 while on loan. At Oldham he helped the Lancashire side to the Division 2 title in 1991 and promotion to Division 1(which became the Premiership a year later.) His greatest success as a player came with Aston Villa where in his first 6 months at the club they finished runners up in the Premiership and in 1993/94 won the League Cup beating Manchester United 3-1 at Wembley with Earl playing the full 90 minutes. He was bought by Everton midway through the next season and although they won the FA Cup in May of 1995, Barrett had already been cup tied(at Aston Villa) meaning he could not claim a winners medal. Much of his spell as Everton was dogged with a knee injury and he moved on to Sheffield Wednesday in February 1998 after making 78 appearances for the Merseysiders. Although injury again restricted him at Sheffield Wednesday the club were on a downward spiral and were relegated from the Premiership at the end of Earl's 2nd season with them upon which he retired from playing.
During his footballing career his nicknames were "The Pearl", Perliniho and 'The Earl of Barrett'.
Since retiring from playing he has obtained a degree is sports science and is now working towards his coaching badges. He currently works at Manchester City as an Events Organiser.
In October 2008 he was spotted in the stands whilst attending a Port Vale match. It is understood that he is part of a 5-man consortium interested in taking control of the club.
In 2001 he famously appeared on Celebrity Stars in their Eyes as Marvin Gaye. He came 4th.