Former Norwich City schoolboy Clayton Fortune started to play at the age of 8 for a Sunday league team called Abbey Raiders in the Waltham Forest League. He played left midfield for the U-10's & then went onto primary school and district trials for Newham where he was spotted by Charlton scouts at the age of 11. Between 11 and 13 he played for Senrab Sunday team whose players included Leon Knight , Jermaine Defoe , Lee Bowyer , Ade Akinbiyi & Bobby Zamora.

He left the game for a couple of years and then at 15 went to Norwich City for a short period until a year later when he signed an academy contract for Tottenham Hotspur. He played for Tottenham Hotspur's Under 17 and Under 19 Academy sides in a number of games during 1999/2000. Clayton comes from a footballing family with his father a former apprentice at Tottenham, cousin Jonathan at Charlton and uncle Leo Fortune-West at Cardiff.

In April 2001, various sources (The Dugout, "Mine Eyes Have Seen The Glory) reported that Clayton had joined Bristol City after being released by Spurs. He made his league debut for Bristol City against Peterborough in December 2001.

In June 2004, Clayton was the subject of two bids from Coca-Cola Championship side Preston but they were both knocked back by The Robins, who are reluctant to sell the central defenderr. Bristol City player-boss Brian Tinnion confirmed the bids from Preston before acknowledging his determination to keep Fortune at Ashton Gate. "We turned down a £100,000 offer a little while ago and they've come back with an increased offer of £150,000 but we've rejected that too," Tinnion
told the club's official website. "I see Clayton very much in my plans for next season and I certainly don't want to sell him." But Preston chairman Derek Shaw has revealed his club's offer was £100,000 in excess of what The Robins have stated. Shaw commented: "I can confirm that we have had a bid for Bristol City's Clayton Fortune rejected. However, I have to go on record as saying that the final deal was more near £250,000 rather than the £150,000 that was quoted."

Clayton was loaned to Port Vale at the beginning of November 2005. BBC Ceefax reported on 24th April 2006 that Bristol City had accepted an undisclosed fee from the Valiants for Clayton's permanent transfer although this was contradicted by reports on 9th May 2006 that Clayton had been released by the Robins. On 7th July 2006, it was announced that Clayton would be training with Derby County.

On 2nd August 2006, Clayton returned to London signing a two-year contract with Leyton Orient. He returned to Port Vale on 22nd November 2006 on a loan transfer

Clayton was one of six players, along with Jabo Ibehre, Wayne Corden, Sam Oji, Efe Echanomi and Raphael Sylvester, told by Orient on 8th May 2008 that the club would not be renewing their contracts. Clayton signed for Darlington on 28th June 2008.

Clayton joined Conference side Rushden & Diamonds on a one-month loan deal on 6th November 2008. He made his debut on 8th November in a 1-0 Conference win over Weymouth.

On 23rd July 2009, Clayton signed for Conference South side Weston-Super-Mare. He made a total of 31 appearances, scoring five goals for the club, who narrowly escaped relegation

In July 2010, Fortune signed a one-year contract with Aldershot Town after impressing on trial. He made just three league starts, and was not offered a new contract at the end of the season.

He signed with Southern League side Mangotsfield United in June 2012, in what was described as a "huge coup for the club".Fortune made his debut for Mangotsfield in a 1–0 home defeat to Cirencester Town on 18th August. On 3 October, he moved up a division to join Chippenham Town, having impressed against the club in an FA Cup clash with Mangotsfield. However he left the club just four weeks later after playing just two games; manager Nathan Rudge said that he "never really got going with us."