<p>This study draws on a co-creational perspective and social identity theory to understand how organizations’ co-creational communication practices shape employees’ moral behaviors to corporate social irresponsibility (CSI). It focuses on two internal communication practices—dialogic communication on moral issues and employee participative CSR decision-making—and examines their effects on employees’ moral internal voice and external whistleblowing via organizational identification. Across two studies with full-time employees, an online survey (Study 1, <i>n</i> = 751) and vignette-based experiment (Study 2, <i>n</i> = 240), the findings showed that both practices significantly enhanced employees’ organizational identification, which in turn increased their moral internal voice, while having no significant effect on external whistleblowing. Together, our findings offer an integrated perspective on the interplay among internal communication, organizational identification, and employee moral behavior in ethically challenging organizational settings and provide practical implications for fostering ethical organizational environments.</p>