Judd was born in Chelmsford, Essex, England. He appeared in Busted's music video for their single "Crashed the Wedding", after which he joined McFly following auditions.

In January 2005, McFly guest-starred in an episode of the long-running British drama series Casualty. In 2007 McFly appeared in BBC television series Doctor Who, with a short cameo role. In May 2006, they starred in the teen comedy film Just My Luck with Lindsay Lohan and Chris Pine, which was released in the US on 12 May 2006 and in the UK on 30 June 2006. They played themselves in the film and the soundtrack featured a variety of their songs from their first two albums. During filming, rumours sparked of a relationship between Judd and Lohan. However, Lohan's reps denied this and said that it was just a publicity stunt. Judd insists that it was just a fling. Judd has also appeared on the BBC panel show Never Mind the Buzzcocks.

Judd appeared on the Channel 4 show Hollyoaks with his band Mcfly on 8th May 2009. They appeared as themselves and played their song "Falling In Love" in a concert, which they performed outside the SUBar.

Alongside his fellow band mates in McFly, Judd is often on TV programmes including The Paul O'Grady Show, T4's Freshly Squeezed and BBC programme Sound.

In 2007, McFly opened the first ever UK Kids Choice Awards on Nickelodeon.