This thesis explores the possibilities for ecocritical study in fiction through John Steinbeck’s 1939 novel The Grapes of Wrath. Major ecocritical interpretation has yet to gain much traction in novels; by focusing on human nature, this form’s “anthropocentric” posture seems itself to be antithetical to ecocritical efforts, which aim to unseat humans as the center of the moral universe. However, by analyzing The Grapes of Wrath’s formal, narratorial, and thematic valences, I argue that principles of social justice concurrently imply environmental justice in the philosophical currents of the text. Tenets of deep ecology and Aldo Leopold’s “land ethic” inform the novel’s overall environmental outlook. The key to my interpretation is the value of community at the center of Steinbeck’s world. To expand principles of the collectivism and compassion in the social community to include the broader ecological community, I focus on the narrative’s unique Judeo-Christian spirituality and humanistic discourse. Ultimately I identify cohesion in The Grapes of Wrath’s composition that makes a single narrative of both the natural and the human worlds, and that creates a moral universe that guides ethical behavior towards others, both human and non-human; in doing so, I argue Steinbeck’s novel both enacts and represents an ecologically minded ethic