Osteoarthritis (OA) is a major social and economic burden that continues to grow globally with no effective disease modifying therapies in the pipeline. Current therapeutic strategies to address pain are largely insufficient and joint replacement for end stage disease is unsustainable. Drug development is particularly difficult and expensive due to the complexity of balancing efficacy and toxicity for chronic diseases. The main risk factors for developing OA are increasing age and obesity. Diet has a clear link to the latter, but also impacts strongly on the ageing process. There is no paucity of pre-clinical data investigating dietary bioactives and their impact on OA disease models. However clinical trials that test these data using relevant trial design and validated outcome measures are scarce. Current trials focus on vitamin D, fish oil omega fatty acids and curcumin. This review examines recently completed, current or proposed clinical trials of dietary bioactives and their utility in developing an OA therapeutic strategy either prophylactically or as a means of OA management. The number of scientifically high quality trials in the pipeline is low. There is an unmet need for investment in clinical trials of dietary intervention, for developing disease biomarkers (both biochemical and imaging) and refining the definition of OA so that clinically relevant outcome measures can be improved.