Martin has been Chief Executive at St John Ambulance since January 2018. He has a strong track record in leading the development of public service delivery and in policy change with a focus on giving people – especially young people – the chance to fulfil their potential through volunteering, education, and training. St John, in his time, has led the volunteer vaccination effort for England, introduced the national NHS Cadet programme and pioneered work with young people at risk of street violence.

He was Chief Executive of Depaul UK for five years, where he saw the charity's work grow, especially the ground-breaking Nightstop service providing hosts for young people at risk on the streets. While at the charity Missing People, he successfully campaigned for a new missing person’s law and launched the new national telephone number for missing people. He has also held roles at the Children’s Society and served as Chair of the YMCA England & Wales board of trustees.

In June 2019, Martin was appointed as Chair of the Centre for Youth Impact which has now merged with the YMCA George Williams College, reflecting his long-term commitment and dedication to making a positive impact on the lives of young adults and children. In 2022 Martin was honoured by his alma mater awarding him an Honorary Doctor of Science in recognition of his work in the voluntary sector and his leadership in the Covid-19 response.

Martin is married to Gareth, with three grown up children and two very fluffy cats. He is a self-confessed aviation geek and flies ultralight aeroplanes.