Statement of Problem The use of banned substances to enhance performance occurs in sport. Therefore, developing valid and reliable instruments that can predict likelihood to use banned substances is important. Method We conducted three studies. In Study 1, football players (N = 506) and athletes from a variety of team sports (N = 398) completed the Moral Disengagement in Doping Scale (MDDS). In Study 2, team sport athletes (N = 232) completed the MDDS and questionnaires measuring moral disengagement in sport, doping attitudes, moral identity, antisocial sport behavior, situational doping temptation, and task and ego goal orientations. A week later, a subsample (n = 102) completed the MDDS and indicated their likelihood to use a banned substance in a hypothetical situation. In Study 3, athletes (N = 201) from a variety of individual sports completed the MDDS and indicated their likelihood to use a banned substance in a hypothetical situation. Results The results of Study 1 showed that one-factor model fitted the data well, and the scale showed measurement invariance across males and females. In Study 2, we provided evidence for convergent, concurrent, discriminant, and predictive validity, as well as test-rest reliability, of the scale. In Study 3, doping moral disengagement was positively related with reported likelihood and temptation to use a banned substance. The scale exhibited very good internal consistency across the three studies. Conclusions In conclusion, the MDDS can be used to measure moral disengagement in doping in team and individual sports.