Globally and in the UK, significant progress has been made in tackling the harms of tobacco use. This was enabled by addressing the fundamental conflict between the tobacco industry’s interests and those of the public, including by rejecting partnerships with the tobacco industry. Conflicts of interest (COIs), like those identified in tobacco control, exist in other areas of public health, yet governments, including the UK, continue to work in partnership with other health-harming industries, including alcohol, ultra-processed food and gambling, despite evidence that partnership approaches where COIs exist are ineffective. This article details lessons that can be drawn from this experience, outlining how understanding and addressing COIs in policy, professional practice and science are prerequisites to tackling commercially driven harms.