The Semaglutide Effects on Cardiovascular Outcomes in People with Overweight or Obesity (SELECT) trial demonstrated significant reductions in cardiovascular outcomes in people with cardiovascular disease (CVD) and overweight or obesity (but without diabetes). However, the cost of the medication has raised concerns about its financial viability and accessibility within healthcare systems. This study explored whether use of semaglutide for the secondary prevention of CVD in overweight or obesity is cost-effective from the Australian healthcare perspective. A Markov model was developed based on the SELECT trial to model the clinical outcomes and costs of a hypothetical population treated with semaglutide versus placebo, in addition to standard care, and followed up over 20 years. With each annual cycle, subjects were at risk of having non-fatal CVD events or dying. Model inputs were derived from SELECT and published literature. Costs were obtained from Australian sources. All outcomes were discounted by 5% annually. The main outcome of interest was the incremental cost-effectiveness ratio (ICER) in terms of cost per year of life saved (YoLS) and cost per quality-adjusted life year (QALY) gained. With an annual estimated cost of semaglutide of A${\$}$4175, the model resulted in ICERs of A${\$}$99853 (US${\$}$143504; £40873) per YoLS and A${\$}$96055 (US${\$}$138046; £39318) per QALY gained. Assuming a willingness-to-pay threshold of A${\$}$50000, semaglutide is not considered cost-effective at the current price. A price of≤A${\$}$2000 per year or more targeted use in high-risk patients would be needed for it to be considered cost-effective in the Australian setting.