Moraghan was born in Toxteth, Liverpool on 27 January 1963. He started acting in 1978, when the BBC held auditions in his high school for the TV play Lies, and he was selected. On 14 May 1988, Moraghan started his professional acting career playing a ferryman in the comedy Help!, and he subsequently went on to play in many TV series and several films. His longest running role was Owen Davies, a Consultant Obstetrician, in Holby City which he played from 2001 until 2005. He also appeared in a television commercial for the fabric softener 'Bounce' in 1996 with fellow Liverpudlian Katy Carmichael. He was recently a member of the cast of the British independent film Allies (2014).