Rickitt is most famous for his role on popular ITV soap opera Coronation Street, where he took over the role of Nick Tilsley in 1997. His girlfriend sent his pictures to various showbusiness agents, one of whom was Nigel Martin-Smith. At first Martin-Smith had the idea of putting him in a boy band he was forming, but when he found out that Coronation Street were re-casting the part of Nick, Rickitt auditioned for the part and got the job. The part had been played by actor Warren Jackson until 1996 when the character moved to Canada.

Rickitt left Coronation Street in 1999 to start a music career. He signed a six-album deal with Polydor, although he only released one album - Good Times - in 1999. Rickitt's first single, "I Breathe Again", reached number five in the UK and was certified Silver by the BPI, but follow up singles "Everything My Heart Desires" (also recorded by Mandy Moore), and "Best Thing" were less successful, reaching no.15 and no.25 respectively. The album was also a commercial failure, peaking at no.41 and dropping out of the chart after only one week. Rickitt was then dropped by his record label, and he abandoned his career in pop music. In 1999, at a performance at The Prince's Trust Party in the Park, a member of the audience sprayed gas onto the stage when Rickitt was performing. Rickitt fainted after inhaling the substance and was taken to hospital.

Rickitt starred as Mark Cohen in the 2002 UK tour of the musical Rent before moving to London's West End. He made a return to the London stage to star in Bill Kenwright's production Office Games, followed by a new play, Final Judgement, and also appeared in Nick Moran's play Telstar on UK tour. In December 2006, Rickitt appeared in his first pantomime, Cinderella, in the role of Prince Charming at the Norwich Theatre Royal.

In October 2005, Rickitt was approved as a prospective parliamentary candidate for the Conservative Party. As part of this attempt to reinvent himself, in February 2006 he appeared on the political debate show Question Time, as the non-partisan guest. In May 2006, he was one of 100 would-be MPs chosen for the Conservative party A-list. The following month, he appeared on Sunday AM with Andrew Marr. He attended national and local Conservative party functions in the hope of being selected as a candidate, and developed a political blog on his website. However, a newspaper article alleged that he was not a member of the Conservative Party and had only decided to support them because of his dislike of then Prime Minister Tony Blair. Rickitt refuted these claims and confirmed that he was a member, while the newspaper retracted its claims the following week. Along with David Cameron, he also provoked the anger of Sir Nicholas Winterton when it was revealed that Rickitt was being tipped to stand for the safe Conservative seat of Macclesfield, which the outraged Winterton had represented for nearly thirty years. Winterton responded that he had no intention of standing down from this seat: "I wish Adam luck, but there are no vacancies here."

In March 2006, Rickitt took part in the Channel 4 reality show The Games. He took part as a replacement, after the scheduled contestant, electronic musician Goldie, had to pull out, following an accident during training for the water ski jump, in which he fractured his femur. Rickitt himself sustained two black eyes after over-rotating off the diving board. He finished last in the contest.

On 21 September 2007, Rickitt was arrested and charged with shoplifting a block of cheese, a bottle of HP sauce and a jar of coffee beans from an Auckland supermarket. During an interview with Herald on Sunday he claimed that it was an honest mistake though later claimed that he was drunk at the time of the incident.

He returned to the political scene in October 2010 as a guest reporter for the ITV breakfast television programme Daybreak covering the Conservative Party Conference from Birmingham, and hosted a conference gay party.

He left in 2013 to begin working with the cancer charity Help Harry Help Others, and Chief Executive of the mental health foundation, the Caerus Partnership.

In 2014, he became part of the supergroup 5th Story, who are taking part in the second series of The Big Reunion along with Kenzie from Blazin' Squad, Dane Bowers from Another Level, Kavana and Gareth Gates.