This chapter clarifies the aims of feminism(s) and feminist theories, broadly, as action-based frameworks for understanding patriarchal systems in order to envision ways they could be different, and strategies for enacting changes towards creating a society based on gender equity. Intersectional theory is highlighted as one feminist theory that fosters social justice through a commitment to creating a more equitable society that recognizes, validates, and celebrates diversity through the theory’s analytical emphasis on a mutually constituted interdependence of social identities, interlocking oppressions and privileges, and multiple experiences of identities. A qualitative feminist research project with young, divorced women is discussed to elucidate some of the ways feminist theory can be mobilized in research for social justice.