The purpose of this randomized noninferiority trial was to compare video teleconferencing (VTC) versus in-person (IP) delivery of an 8-week acceptance and commitment therapy (ACT) intervention among veterans with chronic pain (N = 128) at post-treatment and at 6-month follow-up. The primary outcome was the pain interference subscale of the Brief Pain Inventory. Secondary outcomes included measures of pain severity, mental and physical health-related quality of life, pain acceptance, activity level, depression, pain-related anxiety, and sleep quality. In intent to treat analyses using mixed linear effects modeling, both groups exhibited significant improvements on primary and secondary outcomes, with the exception of sleep quality. Further, improvements in activity level at 6-month follow-up were significantly greater in the IP group. The noninferiority hypothesis was supported for the primary outcome and several secondary outcomes. Treatment satisfaction was similar between groups; however, significantly more participants withdrew during treatment in the VTC group compared with the IP group, which was moderated by activity level at baseline. These findings generally suggest that ACT delivered via VTC can be as effective and acceptable as IP delivery for chronic pain. Future studies should examine the optimal delivery of ACT for patients with chronic pain who report low levels of activity. This trial was registered at ClinicalTrials.gov (NCT01055639).