OBJECTIVE: To evaluate the efficacy of internet-delivered psychological support-the BAck iN the Game (BANG) intervention-after anterior cruciate ligament reconstruction (ACLR) for improving return to sport (RTS). DESIGN: Randomized controlled trial. METHODS: Participants aged 15-30 years, who were playing contact or noncontact pivoting sports at least twice per week prior to anterior cruciate ligament (ACL) injury and intending to return to pivoting sports after ACLR, were included. Participants were randomized to either usual care (UC; standard postoperative treatment) plus the BANG intervention (BANG+UC group) or UC alone (UC group). The intervention was a 24-week internet-delivered psychological support program, codesigned with athletes and clinicians, and based on cognitive behavioral therapy principles. Participants reported sports participation fortnightly after ACLR, and functional and psychological outcomes at 3, 6, and 12 months. Knee function was measured at 12 months after ACLR. New injuries were registered up to 24 months after ACLR. The primary outcome was RTS at the 12-month follow-up. RESULTS: One hundred sixty-one participants were included: 80 in the BANG+UC group and 81 in the UC group. The RTS rate at 12 months was 36% in both groups, with no significant differences in the proportion of those who RTS (risk ratio, 1.01; 95% confidence interval, 0.59-1.73; P = .971) or in functional and psychological outcomes. Twelve participants sustained new ACL injuries (6 in each group), with no between-group differences. CONCLUSION: There was no effect of internet-delivered psychological support on the RTS rate, readiness to RTS, or subsequent knee injuries beyond usual postoperative care for people with ACLR. J Orthop Sports Phys Ther 2026;56(5):310-320. Epub 2 March 2026. doi:10.2519/jospt.2026.13749.