Singapore's implementation of its carbon tax regime in 2019 was largely seen as unprecedented within Southeast Asia. Yet, its success cannot be judged solely on how progressive it was in its enactment alone. This paper offers a critical evaluation of the Carbon Pricing Act 2018 (the "CPA") primarily through the lens of sustainability. It first outlines the general legal contours of the CPA. It is followed by a critical appraisal of the CPA by analysing both its price and its legislative context. The paper demonstrates that, while the CPA is a step in the right direction, it still is vulnerable to the pull of economic priorities which may compromise its environmental pursuits. It concludes by showing that, in order to achieve its carbon reduction objectives, a 'stronger' sense of sustainability would need to be considered and possibly embraced.