After his release from Wolves' academy, Collymore signed for non-league Stafford Rangers, where he caught the eye of First Division side Crystal Palace who signed him in January 1991. He failed to break into the first team and subsequently dropped down to the Second Division (renamed as the First Division in 1992) with Southend United, for whom his goalscoring record helped save from relegation and attract attention from Nottingham Forest, who he joined in the summer of 1993 for £2.25 million. Collymore enjoyed two prolific seasons at Forest, earning promotion to the Premier League in his first season and scoring 22 goals as Forest finished in third place during the 1994-1995 season. Perennial title challengers Liverpool signed him in 1995, where he initially formed a successful partnership with Robbie Fowler, but was eventually ousted in favour of younger striker Michael Owen and sold on to boyhood club Aston Villa in 1997, where his form dipped and he struggled to break into the first team. After two unsuccessful years with Villa, he joined Leicester City in 2000 where he saw a brief career resurgence under Martin O'Neill, but struggled under his successor Peter Taylor and was sold to Bradford City in October 2000, but would leave the club after just 10 weeks due to his high wage bill. He then joined Real Oviedo of the Primera Liga, where he finished his career in March 2001 after just five weeks with the club.