Structured Abstract Objective The aim of this study was to investigate the effects of omega-3 fatty acids on orthodontic tooth movement. Setting and Sample Population For this study, 56 12-week-old adult male Wistar albino rats from the Animal Laboratory at Adnan Menderes University, Faculty of Medicine, were used. Material and Methods Rats were randomly divided into seven groups (n = 8 each): control group (without any treatment), tooth movement groups (three groups of animals with only tooth movement) and omega groups (three groups of animals with tooth movement and omega-3 administration). Omega-3 fatty acids were administered to the rats systemically during the tooth movement period. On the 3rd, 7th and 14th days after the orthodontic tooth movement, the rats were sacrificed and biochemical, histological, immunohistochemical andgene expression examinations were performed. Results On the 14th experimental day, the amount of tooth movement in the omega groups was significantly lower than the tooth movement groups (P = 0.012). Biochemical experimentsshowed that the omega groups had significantly lower total oxidant levels and higher total antioxidant levels compared to the tooth movement group on the 14th experimental day (P = 0.001). The levels of RANKL, IL-6 and IL-1 beta in the omega groups were significantly lower than the tooth movement groups on all experimental days (P < 0.05). Conclusion Systemic administration of omega-3 fatty acids showed antioxidant and antiinflammatory effects and decelerate the orthodontic tooth movement.