With growing public concern over environmental issues, organizations are facing increasing pressure to demonstrate a genuine and measurable commitment to environmental sustainability. In this context, understanding how corporate environmental responsibility (CER) shapes employee engagement (EE) is essential. This understanding helps align organizational behavior with both internal goals and broader societal expectations. Although the impact of corporate social responsibility (CSR) on EE has been widely studied, the specific role of CER—a key subdimension of CSR—remains underexplored. To address this gap, we developed a moderated mediation model grounded in social exchange theory, social identity theory, and signaling theory. This model aims to reveal how CER influences EE and through which mechanisms. Based on survey data from 418 employees in large Chinese manufacturing firms, our results show that perceived CER significantly enhances EE. This effect occurs primarily through the strengthening of organizational pride. Furthermore, online media coverage reinforces the relationship between perceived CER and organizational pride. It also amplifies the indirect impact of perceived CER on EE via this pride. These findings contribute to the corporate sustainability literature by showing how credible and visible environmental actions can enhance employee alignment and engagement. Practical implications are discussed for organizations seeking to connect managerial priorities with society’s call for transparent and authentic environmental initiatives.