The rate of obesity has risen in Malaysia, particularly among university students, due to the COVID-19 pandemic and the implementation of the Movement Control Order. While Acceptance and Commitment Therapy (ACT) has been proven effective in addressing weight-related issues, the combined effects of ACT with a structured exercise program remain unclear. This randomized controlled trial aimed to compare the effectiveness of two ACT interventions for overweight and obese young adults: ACT alone and ACT combined with structured exercise (ACT-EX). The interventions were designed to improve body mass index (BMI) and address weight-related challenges. A total of 102 participants, aged 18 to 25 with a BMI above 23.0 kg/m2, were randomly assigned to the ACT or ACT-EX group. The ACT group took part in six weekly 1.5-h group sessions, while the ACT-EX group participated in the same six ACT sessions, plus three 1.5-h structured exercise sessions per week over six weeks. Data were collected at baseline, post-intervention, and during a 12-week follow-up. The results indicated that the ACT-EX group experienced a more significant reduction in BMI and improved weight-related flexibility, although there were no significant differences between the two groups. These findings suggest that combining structured exercise with ACT can enhance psychological flexibility and assist in weight management.