This paper analyses Singapore’s carbon tax regulations and draws conclusions that can inform the development of a legal framework for a carbon tax in Vietnam. Using a qualitative methodology, the paper analyses documents and policies, and compares the legal frameworks of Singapore and Vietnam. By learning from Singapore’s experience of implementing a carbon tax since 2019, which has achieved effective greenhouse gas emission reductions with a gradually increasing tax rate up to SGD/tonne by 2024, Vietnam could adopt a similar approach with a phased tax increase roadmap and clear emission thresholds. However, these recommendations are based on inferences that lack a clear basis for verification in the Vietnamese context. The paper also provides a model for designing a carbon tax legal framework that is suitable for Vietnam’s economic context. The recommendations aim to promote sustainable development and raise awareness of climate change mitigation by providing a comparative perspective on the application of carbon taxes in Southeast Asia.