Sustainability managers represent a key stakeholder in implementing and diffusing sustainability initiatives. However, there is a significant gap in the literature examining the impact of greenwashing on sustainability managers. This research examines the effects of greenwashing on sustainability managers' job satisfaction, commitment, turnover intentions, and job performance from a social identity/person–organization (P‐O) fit perspective. Our sample consists of practicing sustainability managers (n = 125) in high‐ (77%) or mid‐level (23%) positions. Results indicate that perceived greenwashing negatively affects the attitudinal outcomes (...) and job performance of sustainability managers. The results also indicate that for sustainability managers whose social responsibility identity is higher than that of their firm, greenwashing has a significant association with lower satisfaction and job performance and higher intentions to leave. However, for managers whose social responsibility identity is lower than that of their firm, employer greenwashing had no effect on the sustainability managers' attitudes, even though they recognized their own poor job performance. The cumulative effect may be a situation in which managers in the best position to enhance a firm's CSR leave the firm, and vice versa. (shrink)