Shareholders have become increasingly active in endeavouring to influence companies’ environmental and social practices. In comparison with the mature field of financially motivated shareholder activism, limited enquiries have been carried out on its non-financial counterparts. This paper synthesizes the knowledge base through a review of the academic literature, exploring shareholder activism intended to affect corporate environmental and social performance. Theoretical perspectives appropriate to this phenomenon are critically appraised: in particular, insights from social movement theory, Hirschman's theory of exit, voice and loyalty and stakeholder salience theory, as well as the roles of signalling and symbolic management actions. Data from the literature are organized into a process model of non-financial shareholder influence. Underpinned by the influencing context, this conceptualization centres on three primary shareholder interventions: divestment, dialogue and shareholder proposals. These interventions are enabled through a range of actors and tools: coalitions, non-governmental organizations, codes and indices, the media and regulators. The interaction between interventions and the enabling actors and tools helps to determine managers’ perceptions of shareholder salience. These perceptions subsequently shape the organizational behaviours that affect companies’ symbolic and substantive environmental and social performance. An agenda to direct future research in this burgeoning field is articulated.