Global urbanisation has consequences for human health and relationships with the natural environment. While urban greenspaces are theorised to support health and wellbeing, the role of biodiversity as a mechanism supporting this process is yet to be fully quantified. This review aimed to evaluate existing evidence for a relationship between biodiversity of greenspace and human health and wellbeing, including both self-reported and clinical outcomes. We conducted a systematic database search, thorough article screening and quality assessment, conducting a review of five previous reviews and narrative synthesis of the ten recent studies meeting our inclusion criteria. We also performed a bibliometric analysis of 1,758 studies to chart geographical and temporal trends on the topic. Results revealed that few reviews have holistically analysed the evidence for a relationship between biodiversity in greenspaces and human health directly, finding mixed, or weak evidence for a relationship between biodiversity and various aspects of physical and mental health. Our narrative review discovered evidence supporting associations between health and floral biodiversity, particularly subjective wellbeing and self-reported health, with mixed evidence for other health outcomes or more holistic measures of biodiversity. Consistently defined terminology and integrated methods are required for further research to understand long-term health impacts of exposure to biodiversity through larger-scale longitudinal and controlled case-studies