Background: Chronic pain is common and challenging to treat. Although cognitive behavioral therapy (CBT) is efficacious, its benefit in disadvantaged populations is largely unknown. Objective: To evaluate the efficacy of literacy-adapted and simplified group CBT versus group pain education (EDU) versus usual care. Design: Randomized controlled trial. (ClinicalTrials.gov: NCT01967342) Setting: Community health centers serving low-income patients in Alabama. Patients: Adults (aged 19 to 71 years) with mixed chronic pain. Interventions: CBT and EDU delivered in 10 weekly 90-minute group sessions. Measurements: Self-reported, postintervention pain intensity (primary outcome) and physical function and depression (secondary outcomes). Results: 290 participants were enrolled (70.7% of whom were women, 66.9% minority group members, 72.4% at or below the poverty level, and 35.8% reading below the fifth grade level); 241 (83.1%) participated in posttreatment assessments. Linear mixed models included all randomly assigned participants. Members of the CBT and EDU groups had larger decreases in pain intensity scores between baseline and posttreatment than participants receiving usual care (estimated differences in change scores-CBT: - 0.80 [95% CI - 1.48 to - 0.11]; P = 0.022; EDU: - 0.57 [CI, - 1.04 to - 0.10]; P = 0.018). At 6-month follow-up, treatment gains were not maintained in the CBT group but were still present in the EDU group. With regard to physical function, participants in the CBT and EDU interventions had greater posttreatment improvement than those receiving usual care, and this progress was maintained at 6-month follow-up. Changes in depression (secondary outcome) did not differ between either the CBT or EDU group and the usual care group. Limitations: Participants represented a single health care system. Self-selection bias may have been present. Conclusion: Simplified group CBT and EDU interventions delivered at low-income clinics significantly improved pain and physical function compared with usual care.