BACKGROUND: Preventing violence against children begins with current and accurate data on its scope and nature. Such information on violence against children in the United Kingdom (UK) was most recently collected nationally in 2011 and requires updating. A national research organisation in the UK has carried out a feasibility study on whether and how a national prevalence survey on violence in childhood can be conducted. OBJECTIVE: Phase two of this study includes the development of a questionnaire to collect information on childhood experiences of violence from participants aged 11-25. The aim of this paper is to report on the process of creating the questionnaire. PARTICIPANTS AND SETTING: Data collection was conducted with both UK-based and international child abuse and violence researchers and professionals, adults and children with lived experience of violence in the UK, and children and young people in the target age group in the UK. METHODS: The multistage development and validation process was extensive and thorough. It included a Delphi survey, focus groups, cognitive interviews, and individual consultations. Thematic analysis was conducted to identify feedback by violence type. RESULTS: The final questionnaire includes the following topics: physical abuse, corporal punishment, emotional abuse, neglect, witnessing domestic violence, sexual abuse, peer and sibling violence including bullying, criminal exploitation, community violence, and dating violence as well as factors associated with violence (risk factors, protective factors, outcomes). CONCLUSIONS: Relevance, comprehensibility, and comprehensiveness of items was established, and the questionnaire shows good content validity for use with the target age range in the UK.