There are some key and unique properties of groups concerned with environmental practices in the material flows of everyday life, here called sustainable materialism. These movements embody a range of motivations and discourses, in particular in response to perceptions of the power, injustice, and ecological impact of problematic food systems, energy systems, and various supply chains that provide for everyday needs. Activist conceptions of sustainable materialism are examined, and contrasted with alternative theoretical frameworks of environmental - and materialist - activism, from postmaterialism, through lifestyle politics, to sustainable consumption. Sustainable materialist movements are posited as a different and unique category of political movement - one that is based in collective action, sustainable material practices, and prefigurative politics - which cannot be captured by existing theories and frameworks.