Adrian Crompton was born and grew up in the Forest of Dean, in Gloucestershire, where he still lives today with his wife and two children. After studying Economics at Bath University, he lived and worked in Paris before embarking on a career in parliamentary service in the House of Commons. After a brief period as a government statistician, he moved to the newly established National Assembly for Wales (now, the Welsh Parliament/Senedd Cymru). Adrian undertook various roles at the Senedd before becoming Director of Assembly Business and senior procedural advisor to the Llywydd in 2007. 

Between 2014 and 2018, Adrian worked as an Associate for Global Partners Governance, a social purpose company strengthening parliamentary democracy and political institutions in countries around the world. His expertise and practical support to senior politicians and civil servants was at the heart of projects nurturing democratic reform in Sudan, Iraq, Egypt and Jordan. 

In March 2018, Adrian was recommended by the Senedd for appointment as the Auditor General for Wales and was formally appointed to the position by HM The Queen with effect from 21 July 2018. 

As Auditor General for Wales and Chief Executive of Audit Wales, he leads an organisation of around 270 staff auditing the spending and performance of most of the Welsh public sector.