Martin was born and raised in Gosforth in Newcastle-Upon-Tyne. He has lived in East Lothian since 2004 and worked as a teacher at Prestonpans Primary School from 2007 until his election on 8 June 2017.
Before becoming a teacher, Martin had achieved a BA (Hons) Business Law degree from Huddersfield Polytechnic and worked as a Solicitor between 1989 and 2001. He retrained as a teacher at the University of Edinburgh, achieving a PGCPE pass with merit in teaching in 2002.
Martin has been a member of the General Teaching Council for Scotland (GTCS) since 2015. He has also been an active member of the EIS teaching union.
In Parliament, he is a member of the Science and Technology Select Committee. He is Joint Vice-Chair of the All-Party Parliamentary Group (APPG) for the Timber Industries, the APPG on Fair Business Banking and the APPG on Park Homes. He is also Co-Honorary Treasurer of the APPG on the Prevention of Sexual Violence in Conflict Initiative and an Officer of the APPG on Broadband and Digital Communication.
Outside of his professional life, Martin has been actively involved in the local community since moving to the county, latterly serving as Chair of Prestonpans Community Council.
Martin lives in Prestonpans with his wife Rachel and their two sons.