BACKGROUND: There is a lack of integrated treatment for chronic pain and opioid use disorder (OUD). Yoga and physical therapy (PT) may improve pain and physical function of people living with (PLW) chronic low back pain (CLBP) and may also reduce opioid craving and use, but PLW with OUD face barriers to accessing these interventions. We hypothesize that compared to treatment as usual (TAU), providing yoga and PT onsite at opioid treatment programs (OTPs) will be effective at improving pain, opioid use, and quality of life among people with CLBP and OUD, and will be cost-effective. METHODS: In this hybrid type-1 effectiveness-implementation study, we will randomly assign 345 PLW CLBP and OUD from OTPs in the Bronx, NY, to 12 weeks of onsite yoga, onsite PT, or TAU. Primary outcomes are pain intensity, opioid use, and cost-effectiveness. Secondary outcomes include physical function and overall well-being. DISCUSSION: This trial tests an innovative, patient-centered approach to combined management for pain and OUD in real-world settings. We rigorously examine the efficacy of yoga and PT onsite at OTPs as nonpharmacologic, cost-effective treatments among people with CLBP and OUD who face barriers to integrated care.