Introduction Smoking is still the most preventable cause of cancer, and a leading cause of premature mortality and health inequalities in the UK. This study modelled the health and economic impacts of achieving a ‘tobacco-free’ ambition (TFA) where, by 2035, less than 5% of the population smoke tobacco across all socioeconomic groups.

Methods A non-linear multivariate regression model was fitted to cross-sectional smoking data to create projections to 2035. These projections were used to predict the future incidence and costs of 17 smoking-related diseases using a microsimulation approach. The health and economic impacts of achieving a TFA were evaluated against a predicted baseline scenario, where current smoking trends continue.

Results If trends continue, the prevalence of smoking in the UK was projected to be 10% by 2035—well above a TFA. If this ambition were achieved by 2035, it could mean 97 300 +/- 5 300 new cases of smoking-related diseases are avoided by 2035 (tobacco-related cancers: 35 900+/- 4 100; chronic obstructive pulmonary disease: 29 000 +/- 2 700; stroke: 24 900 +/- 2 700; coronary heart disease: 7600 +/- 2 700), including around 12 350 diseases avoided in 2035 alone. The consequence of this health improvement is predicted to avoid £67 +/- 8 million in direct National Health Service and social care costs, and £548 million in non-health costs, in 2035 alone.

Conclusion These findings strengthen the case to set bold targets on long-term declines in smoking prevalence to achieve a tobacco ‘endgame’. Results demonstrate the health and economic benefits that meeting a TFA can achieve over just 20 years. Effective ambitions and policy interventions are needed to reduce the disease and economic burden of smoking.