We developed the Children's Sport Locus of Control Scale (CSLCS) based on Rotter's (1954) social learning theory. Participants were 750 fifth-and sixth-grade elementary school students. We developed the scale through a series of analyses, including item analysis, exploratory and confirmatory factor analyses, simultaneous multigroup covariance analysis, and criterionrelated validity analysis. The CSLCS comprises 12 items, of which 6 items measure ability and responsibility in the internal control dimension, and 6 items measure environment and chance in the external control dimension. The results of the analyses confirmed that this scale has good reliability, validity, and measurement invariance, and that it also satisfies all fit measures. The 6 measures of internal locus of control in the CSLCS are suited for measuring children's sport locus of control, and the measurement results will not differ across gender. Finally, we offer suggestions to future researchers.In 1966, Rotter developed the concept of locus of control from his 1954 social learning theory, in which it is stated that people learn behavior primarily by observing and imitating the actions of others, and that they increase or decrease behavior according to whether or not they are rewarded or punished, respectively, for their actions. Locus of control refers to one's belief in how much control he or she has over life events, and was described by Rotter (1966) as a problem-solving generalized expectancy. Rotter (1966) identified two types of locus of control, SOCIAL BEHAVIOR AND PERSONALITY, 2015, 43(2), 315-326