When he was younger Alderton was a goalkeeper with Southend United before moving on to comedy. In 2004 the club re-signed him after injuries weakened their squad, following his performance in goal for the Celebrities team in the Sky One reality television series, The Match.
In 1999, Alderton was nominated for the Perrier Comedy Award. Later that year, television producer Johnny Finch himself attempted to launch his own BBC TV show dedicated to video games titled Bleeding Thumbs. The series would have run between 1999-2000 and had hoped to emulate the success the 1990s Channel 4 show GamesMaster achieved, which Finch was on the production team of as well as being a co-commentator. Two pilots were created hosted by Dermot O'Leary and Kate Thornton, and then Alderton accompanying Thornton, the commissioning editor decommissioned the show claiming that "People want to play games, not watch them".
Alderton went on to present the National Lottery show "Red Alert" with Lulu later that year. In 2001 he hosted The Joy of Text with Ulrika Jonsson. He has also presented his own show on Capital Radio called "Terry's Turnstiles". He was also confirmed as a presenter on Setanta Sports News channel.
Alderton currently presents a number of video shows on Virgin Media Sport. His characters include Mr Sheepskin and Danny Dire. He made his West End London début when he performed his one man show at The Bloomsbury Theatre on 21 May 2010.