Over the last century, the intensification of agriculture with high inputs of synthetic pesticides and fertilisers combined with monocrop specialisation has been detrimental to the diversity of genetic resources of crop varieties and livestock breeds, to the wild flora and fauna species and to the diversity of ecosystems. Higher levels of biodiversity can strengthen farming systems and its resilience under changing environmental conditions. This chapter gives an overview of the impact of organic farming on biodiversity. The chapter considers land-use intensity, the impact of organic farming on biodiversity, biodiversity at different spatial scales and the impact of organic farming on selected functional groups. Finally, the chapter discusses some examples of the application of functional agro-biodiversity to boost key ecosystem services on organic farms, and looks ahead to future research trends in this area.