This chapter discusses quality in organic milk – so a useful starting point might be to define what is meant by ‘quality’ and why it matters. The quality of organic milk is important for processors converting raw milk into a myriad of dairy products, is relevant for dairy consumers but also wider society, as well as the farmers. The obvious aspects of quality are things we can measure and quantify in milk and dairy products. These include key nutrients such as minerals, protein and fat compositions, possible contaminants like pesticide or drug residues, or maybe microbial activity and associated mycotoxins. However, many consumers opt for organic products based on their extrinsic qualities (Aertsens et al., 2009), many of which might be intangible or lacking evidence at the point of sale, without further investigation. The most obvious aspects in this category are the impact of production systems on animal welfare, biodiversity and climate change but might also include fair treatment of everybody along the supply chain. Another highly relevant and topical aspect might be the influence of the production system on antimicrobial resistance and the evolution of superbugs.