After appearing briefly in the late night Hollyoaks: In the City, Richardson was offered the role of Ste Hay in the early evening Hollyoaks where he appeared for 19 episodes. The character was written out of the show after stealing a car, which resulted in a spectacular crash and his character getting sent to prison. He returned to Hollyoaks on 25 September 2007, and has been a regular cast member since.
On 15 September 2010, Richardson revealed on television programme This Morning that he is gay, and accepted it at the age of 20. He was inspired to come out by Joe McElderry. In July 2014, Richardson received a torrent of homophobic abuse via social networking site Twitter. That month Richardson announced his intention to marry long-term partner Carl Hyland the following year. In April 2015, the couple were married in a star-studded ceremony in the Peak District.