Over the past decade, digital media have become an increasingly widely used mode of delivery for health interventions, and this trend is likely to continue. Digital interventions are attractive to providers because of their potential for wide reach at low cost per person, and are valued by users as they can provide convenient, private, instant access to automated, expert and peer support. However, the promise of digital interventions has not yet been realised; often effect sizes are small and the market has already become saturated with untested and unhelpful apps and websites. This talk illustrates how the ‘person-based approach’ to intervention development (which is applicable to digital and non-digital interventions) can produce accessible, engaging and effective health interventions. After describing the approach and explaining how it can be integrated with existing theory- and evidence-based approaches to intervention development, examples of how it has been employed to develop effective interventions will be presented. The development of the POWeR intervention for weight management in primary care and public health will be presented in detail. Brief illustrations will also be provided of the value of the person-based approach in the development of the GRACE/INTRO intervention to change GP antibiotic prescribing behaviour, the Balance Retraining intervention to help primary care patients self-manage dizziness and the PRIMIT intervention to reduce infection transmission through improved hand hygiene.