Joel Nirmalan Defries was born on 14 March 1985 in Hammersmith, London. Details about his parents are not publicly confirmed, though he spent parts of his youth in India and New Zealand alongside his upbringing in London. He is Jewish but describes himself as not religious, having visited a synagogue only twice.

Defries began his broadcasting career at age 19 as a host on New Zealand’s C4 music channel, where he fronted shows like Vodafone Select Live from 2005 to 2007. He also hosted the live music show Live at Yours and presented a Sunday morning radio show on The Edge FM called Joel’s Take Out, becoming a household name among young New Zealanders.

On 5 September 2008, it was announced he would replace Gethin Jones as the 34th presenter on Blue Peter, joining the team of Andy Akinwolere and Helen Skelton on 23 September 2008. During his tenure, a pivotal episode called “Joel’s Journey” aired on 27 January 2009, in which he explored his Jewish heritage and visited Auschwitz, where he met Holocaust survivor Freda Winemann. Joel announced on 29 November 2010 that he would be leaving the show on 14 December 2010.

Following his departure from Blue Peter in 2010, Defries worked for two years as a community support worker aiding homeless individuals with housing and recovery from addiction and abuse. In 2015, he entered the spirits industry as Marketing and Brand Manager for the boutique Our/London vodka distillery in Hackney.