Drawing on ecological economics, post-development studies, and political ecology, this paper argues that sustainable development notions have run their course within sustainability marketing debates and proposes degrowth as an alternative framework to steer disciplinary debates in new directions. We chart unexplored territory, offering sustainability marketing scholars tools to navigate degrowth-minded policies, transformative frameworks, and business models. In doing so, our work contributes to existing sustainability marketing debates in three ways: first, we respond to the paucity of studies engaging with the political economy of sustainability marketing. Second, we make visible the tensions and contradictions that arise as marketers seek to reconcile imperatives of economic growth and sustainability. Finally, we foreground degrowth as an emerging sustainability proposition, with potential for inspiring the radical set of transformations required to avert catastrophic climate change and keep global temperatures well below +2°C (relative to pre-industrial levels), as pledged in the Paris Agreement.