This study aimed to investigate the association of locus of control (LOC) with reading and mathematics achievement of high school students with disabilities using data from the Special Education Elementary Longitudinal Study (SEELS). Data used in analysis for the current study included achievement and self-concepts measures from students with learning disability (n = 352), students with speech impairment (n = 112) and students with emotional disturbance (n = 220). Through hierarchical linear regression the authors evaluated LOC and its influence on reading and math achievement. Two reading measures (i.e. oral reading fluency, passage comprehension) and two math measures (i.e. calculation, applied problems) were examined, as well as the impacts of demographic factors (i.e. age, gender, ethnicity and socioeconomic status). Results showed that (a) negative correlations between LOC scale scores and achievement were identified for all three subgroups; (b) the correlation coefficients between LOC and achievement scores were similar across three subgroups; (c) the extent to which LOC and/or demographic factors influenced on achievement varied according to reading and math task, as well as disability category. Based on these findings, the role of LOC in improving academic achievement of students with disabilities and the implications to practise and future research were discussed.