Previously Head of Libraries, Information and Learning with Glasgow City Council, Martyn has worked in public libraries, including professional posts in Cambridge and Leicestershire.
He has been a professional librarian for over 40 years, focusing on intellectual freedom and freedom of expression, and the value of historic library collections.
He has placed a great emphasis on breaking down barriers to the use of library, information and archive services to widen the use, understanding and enjoyment of collections and services.
Martyn is Chair of the Advisory Committee for Copyright and Other Legal Matters of the International Federation of Library Associations and Institutions. He is also Chair of the Policy Committee of the Chartered Institute of Library and Information Professionals.
A governor of Innerpeffray Library, Martyn is a trustee of the Scottish International Education Trust.
He is a Visiting Professor at Robert Gordon University in Aberdeen, an Honorary Fellow of the Department of Information Studies at the University of Aberystwyth and was awarded an OBE for services to culture in Scotland in 2014.