OBJECTIVE:This study aimed to assess population-level cost-effectiveness of the Weight Watchers (WW) program with doctor referral compared with standard care (SC) for Australian adults with overweight and obesity. METHODS:The target population was Australian adults ≥ 20 years old with BMI ≥ 27 kg/m2 , whose obesity status was subsequently modeled for 2015 to 2025. A microsimulation model (noncommunicable disease model [NCDMod]) was used to assess the incremental cost-effectiveness of WW compared with SC. A health system perspective was taken, and outcomes were measured by obesity cases averted in 2025, BMI units averted for 2015 to 2025, and quality-adjusted life years for 2015 to 2025. Univariate sensitivity testing was used to measure variations in the model parameters. RESULTS:The WW intervention resulted in 60,445 averted cases of obesity in 2025 (2,311 more cases than for SC), extra intervention costs of A$219 million, and cost savings within the health system of A$17,248 million (A$82 million more than for SC) for 2015 to 2025 compared with doing nothing. The modeled WW had an incremental cost-effectiveness ratio of A$35,195 in savings per case of obesity averted in 2025. WW remained dominant over SC for the different scenarios in the sensitivity analysis. CONCLUSIONS:The WW intervention represents good value for money. The WW intervention needs serious consideration in a national package of obesity health services.