Former England Youth international Andy Johnson left Norwich City in July 1997 to join Nottingham Forest for £2.2 million. The final months of his career somewhat overshadowed his achievements for the Canaries and lost him the respect of the Carrow Road crowd.

Bristol-born Andy joined Norwich as a trainee and captained the Youth side. He signed professional forms in July 1990 and made his league debut against Sheffield Wednesday in April 1992. The following year, he began to establish himself in the first team but was called upon to represent England at the World Youth Championships in Australia. He failed to re-establish his place on return from down under and had a couple of disappointing years with the Canaries. He made his mark in Norwich's Division One campaign in 1995/96. He occupied a central midfield role combining strong tackles with an eye for goal. He made a total of 30 appearances that season scoring 8 times. He began well under Mike Walker during the 1996/97 season but as Norwich slipped further away from the promotion places, Andy grew more disappointed. He later stated "I felt I was going stale; that with a move to a big club like Forest I could fulfill a few of my ambitions in football. I couldn't have stayed - I've been here ten years; I needed a move." He also suffered niggling injuries and this frustration spilled over onto his disciplinary record. A fracas between him, Carl Bradshaw and a local taxi driver led to assault charges being filed against him. He submitted a transfer request in the early part of 1997 and was effectively frozen out of the first team. He made 27 appearances that season for Norwich netting 5 times.

Nottingham Forest submitted a £2.2 million bid for him which was finally accepted despite Norwich's attempts to up Andy's price to £2.5 million. Late bids from Martin O'Neill's Leicester City and Crystal Palace also failed to knock the Forest deal off course. With Forest winning the Division One championship, a clause in Andy's transfer generated an extra £300,000 for the Carrow Road coffers.

Discovering that his grandmother was Welsh, Andy was called up by Bobby Gould into the Welsh international squad and made his debut in the 2-0 defeat against Italy on September 6th 1998.

Sport First, on 30th May 1999, claimed that Leicester manager Martin O'Neill was planning a £2.5million swoop for Andy Johnson. In August 2000, Andy was linked with a move to Birmingham City in exchange for Zimbabwe winger Peter Ndlovu whom Forest manager David Platt had supposedly wanted at City Ground for some time. In November 2000, the Unofficial Football Transfers website reported that Andy was a target for ambitious Welsh club Cardiff City. In July 2001, it was suggested that West Ham saw Andy Johnson as a midfield target if they were unable to secure first choice signing Lee Carsley from Coventry. In August 2001, Forest put all their players on the transfer list as a result of the club's financial predicament. Johnson also had a falling out with new manager Paul Hart and refused to be only a substitute. Johnson said that he would seek a move and that a return to Norwich would be appreciated as he "had some great years at Norwich and always got on well with everyone there." Nigel Worthington stated that he had no need for another central midfielder especially with the wages that Andy commanded. Cardff City again expressed an interest in signing Johnson. Andy's nightmare at The City Ground ended when he joined Gary Megson's West Bromwich Albion for a fee reported to be either £100,000 or £200,000 depending which paper one reads.

Despite promotion to the Premiership, Andy submitted a transfer request in mid August 2002 as the new contract he had been offered was not deemed suitable for a Premiership player (in Andy's opinion).

In March 2003, speculation was rife that Leicester would approach West Brom to sign Andy for £500,000 if Leicester were promoted to the Premiership. This story has even more to support it following the football results from 19-21 April 2003 that saw Leicester promoted and West Brom relegated. Squeezed out of Megson's first team plans by the signing of James O'Connor (Stoke) and Artim Sakiri (Macedonia), Johnson was allegedly the subject of a £250,000 bid from West Ham on August 20th 2003. In the end, Andy stayed with the Baggies and helped them win promotion back to the Premiership

On January 8th 2006, The People reported that Bristol Rovers were preparing a £350,000 bid for Johnson. The following week saw the News of the World claim that Preston manager Billy Davies had joined the hunt for Johnson. The People added the same week that Leeds and Notts Forest were also keen on Johnson. On 26th March 2006, the News of the World reported that Sheffield Wednesday and Leicester had approached the Baggies about loaning Johnson before the transfer deadline day but were rebuffed. However Johnson will be allowed to leave the club during the summer when he is out of contract. The following week saw Sheffield United added to the list of suitors according to the League Paper.

On 20th June 2006, Andy signed for Leicester City. He had been heavily criticised for his performances by the City fans, especially in the 2-1 away defeat to Sheffield Wednesday on 4 November 2006. Following that performance, Johnson had a spell on the sidelines through injury, but has since made a comeback and was the man of the match against Luton Town on 3 February 2007. On 25th April 2007,it was announced that having not featured under manager Nigel Worthington, Leicester had begun talks to terminate Johnson's contract early and he was eventually released in May 2007. He had made 21 appearances for Leicester, scoring once.

Andy then signed for Championship rivals Barnsley in June 2007. He was placed on the transfer list by the Tykes in January 2008. He was eventually released by Barnsley in January 2009. After he was spotted playing in a trial match for Kidderminster by Kings Lynn manager Keith Webb, the Linnets made an approach and he was delighted to team up again with Webb who was his former youth team coach at Norwich. Johnson made 17 appearances for the Linnets in the Conference South

In June 2009, he was appointed Assistant Manager at Lynn, having hung up his boots. He will assist new manager Carl Heggs who replaced Keith Webb who stepped down at the end of the 2008/9 season.

Johnson quit Lynn in early September 2009 claiming that he had not been paid money owed to him from the previous season.