Simon was born in Newtownards in 1977. Educated at Regent House School, he then went on to graduate with a BA (Hons) in Modern History and Politics and a BLegSc in Law from Queen’s University Belfast. Simon began his career at a leading Belfast accountancy firm in Belfast.

Simon was first elected to represent the Strangford constituency in the Northern Ireland Assembly in March 2007. He has served as Chair of the Social Development Committee between 2009 and 2011, leading Stormont's scrutiny of the work of the Department in respect of housing, social security, the community and voluntary sector and urban regeneration. Simon was also a member of the Assembly and Executive Review Committee which examines issues such as streamlining Stormont and the devolution of policing and justice powers.

A regular TV and radio contributor, Simon was the winner of the Slugger O’Toole ‘Up and Coming’ Politician of the Year award in 2010. His interests include reading, walking and watching sport. Simon has served as the Democratic Unionist Party’s Director of Elections since 2010, helping oversee the successful election campaigns of 2010 and 2011.