Taxes on sugar-sweetened beverages (SSBs) are recommended as part of comprehensive policy action to prevent diet-related non-communicable diseases (NCDs), but have been adopted by only one quarter of World Health Organization (WHO) Member States. This paper presents a comparative policy analysis of recent SSB taxes (2016–19) in 16 countries. This study aimed to analyse the characteristics and patterns of factors influencing adoption and implementation of SSB taxes and policy learning between countries, to draw lessons for future SSB taxes. The data collection and analysis were informed by an analytical framework that drew on ‘diffusion of innovation’ and theories of policy learning. Qualitative data were collected from policy documents and media, in addition to national statistics. Qualitative data were thematically analysed and a narrative synthesis approach was used for integrated case study analysis. We found adaptation and heterogeneity in the approaches used for SSB taxation with a majority of countries adopting excise taxes, and consistent health framing in media and policy documents. Common public frames supporting the taxes included reducing obesity/NCDs and raising revenue (government actors) and subsequent health system savings (non-government actors). Opposing frames focused on regressivity and incoherence with other economic policy (government actors) and posited that taxes have limited health benefits and negative economic impacts on the food industry (industry). Evident ‘diffusion networks’ included the WHO, predominantly in middle-income countries, and some regional economic bodies. We found indications of policy learning in the form of reference to other countries’ taxes, particularly countries with membership in the same economic bodies and with shared borders. The study suggests that adoption of SSB taxation could be enhanced through strategic engagement by health actors with the policy-making process, consideration of the economic context, use of consistent health frames by cross-sector coalitions, and robust evaluation and reporting of SSB taxation.