This paper develops the concept of ‘critical agrarianism’ to describe and advance the pursuit of land-based work as a means of realizing social justice and environmental sustainability. Encouraging new agrarianism to more carefully scrutinize its agenda, critical agrarianism celebrates the promise of a close working relationship with the natural world while insisting that a return to the land—per se—is insufficient. In the practice of linking people and land, past and present, critical agrarianism continually questions and reshapes the very category of agrarian, toward a more equitable and enduring prosperity. I revisit both canonical agrarian writing and its critics, pulling out ‘back-pocket tools’ that can keep critical agrarians on track in building our alternative futures. I then offer several case studies of critical agrarianism in practice, encouraging a move beyond idealized models of agrarian ties, toward an empirical account of who has actually been doing the work to put food on the table. Noting the historical gap between working the landscape and having a property or citizenship right, I call for an agrarianism in which practices—not land title—are the basis of material and social community. Furthermore, I suggest that agrarianism must extend its web outward rather than inward, forging connections to the work of land tenure reform, education, community development, immigrant advocacy and trade policy. To be a critical agrarian is not to preserve fixed social-natural ties, but rather to practice a powerfully open and dialogical engagement with the world and one another.