Post-traumatic stress disorder (PTSD), prevalent among Veterans, increases risk for having a high Body Mass Index. Although the Veterans Health Administration (VHA) offers an evidence-based behavioral weight management program called MOVE!, participants with PTSD lose less weight than those without mental health conditions, despite comparable participation. PTSD symptoms can interfere with one's ability to be physically active and maintain a healthy diet, the key targets in weight management programs. We developed and piloted a behavioral weight management program called MOVE! + UP that targets PTSD-related weight loss barriers. MOVE! + UP includes 16 group sessions with training in evidence-based weight management strategies, coupled with Cognitive Behavior Therapy (CBT) skills to address PTSD-specific barriers. The 16 sessions also include 30-min community walks to address PTSD-related barriers that may impede exercise. Two individual dietician sessions are provided. This hybrid type 1 randomized controlled trial (RCT) will compare MOVE! + UP to standard care—MOVE!—among 164 Veterans with BMI ≥ 25 who are receiving care for PTSD. We will randomize participants to MOVE! + UP or standard care and will compare absolute post-baseline change in weight at 6 (primary outcome) and 12 (secondary outcome) months, and PTSD symptom severity at 6 and 12 months (secondary outcome). Exploratory analyses will compare the treatment conditions on treatment targets measured at 6 months (e.g., physical activity, eating behavior, social support). Finally, we will estimate intervention costs, and identify MOVE! + UP implementation barriers and facilitators. If effective, MOVE! + UP could be an efficient way to simultaneously address physical and mental health for Veterans with PTSD.