Exposure to nature is thought to benefit mental health and wellbeing. However, many studies consider greenspace as a single entity, which overlooks the potential significance of the various forms of greenspace, and natural greenspaces in particular. This study was designed to investigate the association between different types of greenspace and mental wellbeing. Drawing wellbeing and socioeconomic data from the Annual Population Survey (2012–2015), and shapefiles from the Greenspace Information for Greater London group, the amount of greenspace accessible within a 300 m walk of individual’s postcodes was calculated, and categorised according to type. Spatial Error Models were used to account for spatial patterns in the data. Natural greenspace was significantly associated with improved life satisfaction ( B = 0.028, p < 0.001) and happiness ( B = 0.023, p = 0.019) scores. The spatial autoregressive parameter ([Formula: see text]) was small but significant ( p < 0.001), implying slight second-order spatial variation in the model. These results imply that natural areas may be more important for hedonic mental wellbeing than other greenspaces. Future research is needed on exploring causal relationships between exposure to greenspace and mental wellbeing outcomes.