There is increasing evidence that residential greenspaces (proximity to and amount of green spaces and vegetation around a person's home) may be associated with various health outcomes, including increased physical activity levels and respiratory health outcomes, such as asthma. As lung function is associated with both physical activity and asthma, it could thus also be associated with greenspaces. However, to date, no study has examined whether an association between residential greenspaces and lung function exists in children, and what potential pathways may be playing an important role. Using the ALSPAC data, this study aims to fill this research gap.