David Westlake is a Principal Research Fellow at Cardiff University's School of Social Sciences.

David researches child and family social work, and his career to date has included a wide range of topics and methods. He is currently co-leading the Basic Income for Care Leavers in Wales evaluation, and is the Cardiff lead on an randomised controlled trial (RCT) of a school-based policing intervention led by Kings College London.

David's recently completed studies include the world's largest RCT in social work (the Social Workers in Schools Trial - involving 280,000 children), the evaluation of the Family Drug and Alcohol Court pilot in Wales, and evaluations of parental advocacy.

In 2024 David co-edited a special edition of the Journal of Children's Services, on the topic of education and formal and community-based children’s services, and he has a book about experimental methods in Children's Social Care research due out in late 2025. David is an HCRW 'Advancing Researcher' Fellow for 2025-26, a member of the UK Government's Evaluation and Trial Advice Panel, and part of the School of Social Sciences ethics committee.