Abstract Background This study aims to evaluate the feasibility and acceptability of the PhunkyFoods Programme, a primary school-based intervention to promote healthy nutrition and physical activity knowledge and behaviours to assess outcomes to inform a phase 3 trial. Methods The cluster randomised feasibility trial recruited eight primary schools from the North of England. Elibility criteria included all primary schools in one town, excluding independent and special schools and schools that comprised of only key stage 2 pupils (years 3–6). Eight schools agreed to participate. Randomisation to intervention or control arms was in a 1:1 ratio. Intervention schools received PhunkyFoods over 17 months. Control schools continued with usual curriculum. Assessors were blinded to group assignment. Measures comprised of a Healthy Lifestyle Knowledge Questionnaire and Synchronised Nutrition and Activity Program to assess diet and physical activity, height, weight, and psychological wellbeing. Feasibility outcomes were...