Mark Ian Addy (born 14 January 1965) is an English actor. His roles in British television include Detective Constable Gary Boyle in the sitcom The Thin Blue Line (1995–1996) and Hercules in the fantasy drama series Atlantis (2013–2015).

He made his film debut as Dave Horsefall in The Full Monty (1997), earning a nomination for the BAFTA Award for Best Actor in a Supporting Role. Other notable roles include Fred Flintstone in The Flintstones in Viva Rock Vegas (2000), Bill Miller in the CBS sitcom Still Standing (2002–2006) and King Robert Baratheon in the HBO fantasy series Game of Thrones (2011).

Early life
Addy was born 14 January 1965 in York, where his family has lived since at least 1910 when his paternal great-grandfather was recorded there. His father, Ian, spent his working life as a glazier at York Minster. Addy was educated at Joseph Rowntree School in York. Addy furthered his acting education by attending the Royal Academy of Dramatic Art in London, graduating with an Acting Diploma in 1984. Whilst still at school, Addy had 3 weeks work experience at the York Theatre Royal, loved it so much he continued working there, eventually deciding acting was to be his career goal.