Obesity is a major public health issue in New Zealand. There is an increasing interest in how the environment influences diet. This study aims to assess how the food environment, including marketing and provision of foods, in an organised sport setting impacts children's food and nutrition behaviour. Participants will be selected from the greater Wellington region, providing a mix of ethnicity, rurality and deprivation. A mixed-methods approach, including photovoice, focus groups and a cross-sectional survey will be used to determine the children's viewpoint as well as parental attitudes and perceptions of their children's food environment in organised sport settings. This study would be the first to investigate how the food environment within this key setting shapes young people's food and nutrition behaviours. The findings will be used to build on existing knowledge and inform local, national and international policymakers in developing interventions to promote healthy eating in an organised sport setting.