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 Ligue 1 outfit Montpellier HSC showed interest, but rescinded their offer after Collymore refused to play in a practice match before signing.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.