Gavin was born in Scarborough on 25th June 1976. He went to Raincliffe Comprehensive School and Scarborough Sixth Form College. He gained a Bachelor of Science from the University of Bradford.
After graduation, Gavin began a career in manufacturing, successfully turning around a struggling pottery in Staffordshire. He then became the Managing Director of an architectural design firm which has been involved in the design of many schools, public sector and commercial buildings.
Gavin's involvement in the voluntary sector has been extensive. He has been a Charitable Trustee at his local Citizen's Advice Bureau and a school governor.
Gavin was elected as a County Councillor in 2001, during which time he was involved in community matters, but he has also had a strong interest in education issues. He stood down, in 2005, to contest the seat of Blackpool North and Fleetwood in Lancashire. Afterwards he became Deputy Chairman of Staffordshire Area Conservatives, Chairman of Stoke on Trent Conservative Association and Vice Chairman of Derbyshire Dales Conservative Association.
In 2010, Gavin ran for and was successful in winning the parliamentary seat of South Staffordshire. Since entering Parliament in May 2010, Gavin has become a member of the Northern Ireland Affairs Committee and Chairman of the All Party Group on Motor Neurone Disease. He was also elected to the Executive of the Commonwealth Parliamentary Association and spent three years as co-chairman of the Parliamentary Group on Design, because of his interest in the manufacturing and design sector.
In October 2011, Gavin became Parliamentary Private Secretary to the Rt. Hon. Hugo Swire MP, Minister of State for Northern Ireland. In July 2012, Gavin became Parliamentary Private Secretary to the Rt. Hon. Owen Paterson MP, Secretary of State for Northern Ireland. In September 2012, Gavin moved to become Parliamentary Private Secretary to the Rt. Hon. Patrick McLoughlin MP, Secretary of State for Transport. Most recently, Gavin was appointed Parliamentary Private Secretary to the Prime Minister, the Rt. Hon. David Cameron MP.
In May 2015, Gavin was appointed as a Privy Counsellor by Her Majesty the Queen at Buckingham Palace.
In July 2016, the Prime Minister, the Rt. Hon. Theresa May MP appointed Gavin as Chief Whip (Parliamentary Secretary to the Treasury)
In August 2016, as part of David Cameron's Resignation Honours, Gavin was appointed a Commander of the Order of the British Empire (CBE) for political and public service.
Gavin became Secretary of State for Defence in November 2017.