Sociologists have canonized W.E.B. Du Bois as a theorist of race but have neglected his engagement with environmental themes. Not only was he concerned with ecology, such as the health of soils and water, but environmental themes also figured in his explanations of racism. Du Bois prefigured contemporary scholarship on environmental racism, detailing colonial capitalism’s uneven distribution of environmental benefits—such as natural resources—and harms—such as flooding and pollution. Moreover, Du Bois had novel insights on the role of environmental entities in shaping the adoption of racism, a process I term environmental racialization. He demonstrates how struggles over land led workers to pursue racism rather than solidarity. He argues that capitalist planters adopted racism to blame laborers for degraded soils. Du Bois is one of sociology’s earliest environmental theorists, uniquely illuminating how environment-society relations shape racism.