Background Tobacco companies have maintained a profitable business in Singapore, despite its strong anti-tobacco climate and commitment to protect public health policymaking from tobacco industry interference in line with Framework Convention on Tobacco Control Article 5.3. This study describes how tobacco companies influence policymaking in a highly regulated environment such as Singapore’s, where there is a strong government commitment to Article 5.3.

Methods Analysis of internal tobacco industry documents detailing the industry’s lobbying activities in Singapore, retrieved via snowball searches in the Truth Tobacco Industry Documents Library. Subsequently, we conducted one-on-one interviews with key informants from sectors mentioned in the documents (academia, arts, government, public health, media, trade, education) to fill gaps in information and provide context to events described in the documents.

Results In the 1980s and 1990s, tobacco companies observed that, to influence policy within Singapore’s ‘hostile’ environment, they needed to use ‘behind the scenes’ tactics, targeting influential individuals at social functions or industry-sponsored events. Tobacco companies used arts and education sponsorships primarily for political purposes, to gain visibility with policymakers. Tobacco companies cultivated relationships with academic researchers and the media to avoid smoke-free legislation in the 1990s and, in the 2010s, appear to have used similar tactics to challenge Singapore’s e-cigarette ban.

Conclusions Countries with a strong commitment to Article 5.3 should consider the tobacco industry’s potential interference in policymaking beyond relationships in the government sector, particularly in academia, arts, education and the media, and the more subtle or indirect manners in which these relationships are built.