Academics have different motivations for external engagement, including to acquire external resources for research (research advancement motivation), to contribute to society (prosocial motivation), or to acquire monetary benefits (pecuniary motivation). Universities also have varying policies for rewarding external engagement. This paper examines the relationship between academics’ motivations for engaging, their perceptions of the fairness of their universities’ policies, and their actual level of external engagement. Most academics consider contributing to the betterment of society as the most important reason for engagement, followed by the advancement of their research. Conversely, few academics consider obtaining personal income to be important. The perceived importance of all three motivations is positively associated with actual engagement behavior. Notably, the strength of research advancement motivation is more closely associated with external engagement than the strength of pecuniary motivation. However, perceptions of organizational fairness are not related to external engagement.