Collymore and Aston Villa mutually agreed to separate after he returned from his loan spell at Fulham, and he spent the rest of 1999 training with the youth team and looking for a new club. Ligue 1 outfit Montpellier HSC showed interest, but rescinded their offer after Collymore refused to play in a practice match before signing. Newly promoted Bradford City also tried and failed to sign him, put off by Villa's £3 million asking price. He eventually joined Leicester City for free on a pay-as-you-play basis on 11 February 2000. Just days after signing for the club, he made front page news during a team break in Spain, when he set off a fire extinguisher during a night of drinking inside La Manga Club, which resulted in £700 of damage to the bar and the entire team being sent home. Collymore was fined £30,000 and ordered to undertake community work by boss Martin O'Neill for the incident; O'Neill also warned Collymore that he would terminate his contract if any more incidents like this would occur. After returning to England, his second appearance and home debut for the club saw him score a hat-trick in a 5-2 drubbing of Sunderland. He would score 4 times in 6 appearances in his debut campaign for the Foxes, a season that saw them reach the League Cup Final, where they defeated Tranmere Rovers 2-1, though Collymore, having turned out for Fulham earlier in the season, was cup-tied and unable to feature. Collymore was stretchered off the pitch during a game against Derby County on 2 April after just 17 minutes, having audibly screamed and collapsed in the middle of the pitch. Scans later revealed he had suffered a broken left leg after an awkward landing, and he missed the rest of the season.
Having fully recovered, Collymore remained with Leicester through the summer transfer window and was thought to be the club's new first choice striker after Emile Heskey had left for Liverpool in the summer; however, with Martin O'Neill having departed Leicester to manage Celtic, he was dropped by replacement manager Peter Taylor in favour of new signing Ade Akinbiyi and instead often bought on as a midfield substitute. He scored once more for the Foxes, in a 2-0 win against Chelsea F.C. at Stamford Bridge on 17 September 2000. On 24 September, during a 1-1 draw against Everton, Collymore was alleged to have "stamped on, and later elbowed" Paul Gascoigne. While referee Alan Wiley claimed he did not see the incident and Collymore wasn’t punished during the game, he was later ordered to attend a disciplinary hearing by the Football Association (F.A.) on 28 November. Two days after the incident with Gascoigne, Collymore submitted a transfer request to Leicester. He would later retract this request, but manager Peter Taylor still placed him on the transfer list, citing Collymore's poor fitness, lack of commitment and attitude problems. Having fallen out of favour with another manager, and demoted to the reserve squad, where he was involved in a half time altercation with teammate Trevor Benjamin, Collymore and Leicester would eventually agree to part ways, and he was allowed to leave on a free transfer in October 2000.
Collymore was immediately signed by longtime admirers Bradford City on 26 October 2000, a move described as "desperate" by BBC Sport pundit Mark Lawrenson. He made his Bradford debut in a West Yorkshire derby against Leeds United at Valley Parade on 29 October, scoring a memorable overhead kick in a 1-1 draw, however, his controversial celebration in front of the away crowd caused uproar and led to two Leeds fans being restrained by stewards. Collymore subsequently faced additional charges from the F.A. for the incident. He was substituted at half-time in his second game as Bradford lost 4–3 to Newcastle United in the League Cup, and missed the following game at Charlton Athletic because of flu and a sore wisdom tooth. In Collymore's absence, City lost 2–0, and manager Chris Hutchings was sacked two days later. Jim Jefferies soon took over as new City manager, and Collymore once again lead the front line in Jefferies' first home game in charge against Coventry City, scoring Bradford's first goal. On 28 November, he attended a disciplinary hearing for the incident with Paul Gascoigne while he was still at Leicester, and upon video review of the incident, he was handed a three match ban, which meant he would miss key games against Liverpool, Sunderland and Chelsea. After returning from his ban, Collymore, and other highly paid players Benito Carbone and Dan Petrescu were transfer-listed in January of 2001 by chairman Geoffrey Richmond in a bid to reduce the club's high wage bill. VFB Stuttgart and Celtic both made offers for Collymore, but he would eventually choose to sign with Spanish outfit Real Oviedo after just 8 games and 10 weeks with Bradford.
Collymore made front page news in February 2000 while playing for Leicester City, when, during a team break in Spain, he set off a fire extinguisher during a night of drinking inside La Manga Club which resulted in the entire team being sent home and banned from the resort. Collymore was fined £30,000 and ordered to undertake community work by boss Martin O'Neill for the incident. Later, in December 2000, while playing for Bradford City, Collymore suffered a broken nose after he was assaulted by two men in a Birmingham nightclub. He was subsequently cautioned by manager Jim Jefferies.