Companies have been criticized by employees and activists alike for their insufficient engagement with social and environmental issues. This study examines how consumers respond to public company-directed activism depending on who the activists are, what rhetoric they use, and how consumers perceive the particular issue raised. The results of an online experiment (N = 303) focusing on climate change show that insider activists are evaluated as more legitimate than outsider activists. Outsider activists using aggressive rhetoric are ascribed the least legitimacy compared with outsiders using peaceful rhetoric and insiders regardless of their rhetoric. Furthermore, consumers’ perceived problem and involvement recognition regarding climate change positively influence their evaluation of activist legitimacy. Activist legitimacy, in turn, leads to more negative general attitudes toward the target company and thus higher intentions for negative word of mouth (NWOM). Consumers’ perceived problem, involvement, and constraint recognition also directly affect their NWOM intentions.