Police personnel have long working hours, dangerous duties, and widening police force gaps. These result in high police work pressure and low organizational commitment. Because police personnel use Facebook extensively, the Director-general's Office of the National Police Agency has created a Facebook fan page to implement internal marketing to increase the organizational commitment of police personnel. This study explored the relationship among the use of a Facebook fan page, internal marketing, and organizational commitment. Internal marketing was the independent variable, organizational commitment was the dependent variable, and the use of Facebook fan pages and demographic variables were moderator variables. We used both paper and online questionnaires. The results demonstrate that police officers' perceptions of internal marketing have a positive effect on organizational commitment. The use of fan pages has a positive effect on the perceptions of internal marketing, but demographic variables have no significant effect on internal marketing or organizational commitment. Therefore, the Director-general's Office should supplement its fan page with incentives, understand police big data, and focus on internal marketing on its fan pages to improve the organizational commitment of police personnel.