Dyer started his career as a trainee at Ipswich, playing over 100 times for the club between 1996 and 1999, making the PFA team of the year in the 197-1998 season. Dyer then moved to Newcastle, where he played over 250 times, scoring 36 goals. During this time, Dyer made the England squad for Euro 2000, World Cup 2002 and Euro 2004. He moved to West Ham in 2007. After retiring, Dyer has enjoyed spells as a coach at Ipswich Town.