The prevalence of anti-fat attitudes among kinesiology professionals is concerning because research shows that being subjected to anti-fat attitudes is associated with negative health outcomes and physical activity avoidance. Although anti-fat attitude reduction interventions exist, interventions that teach attribution retraining as a behavior change technique to improve one's negative attitudes toward oneself and others are limited. The purpose of this study was to examine the effects of an attribution theory-based online course on kinesiology students' anti-fat attitudes and self-compassion. Forty-nine undergraduate kinesiology students attending universities in Southern California completed the Anti-Fat Attitude Test (AFAT) and Self-Compassion Scale (SCS) at pre- and post-intervention. Results showed a significant decrease in students' anti-fat attitudes post-intervention. The AFAT scores decreased significantly from 62.76 to 55.35, t(47) = 3.67, p = 0.001, d = 0.53, including the subscales of weight control/blame and physical/romantic unattractiveness. The SCS scores increased significantly from 74.60 to 77.44, t(48) = 3.08, p = 0.002, d = 0.44, including the subscales of self-kindness and common humanity. These pilot results provide initial evidence that attribution retraining may be an effective intervention among kinesiology students to reduce their anti-fat attitudes. Future studies should examine the effects of this intervention compared to a control course and with a larger sample size.