The Fair Lawn Police Department consists of 60 officers, led by chief Erik Rose. Residents petitioned the borough council to establish a full-time paid police force in 1930, and the borough purchased its first police car in 1931. The police roster includes drug abuse resistance education officers, field training officers, Bergen County rapid deployment force members, and traffic accident investigators.

The department's state mission is to protect the lives, property, and rights of all people; to prevent crime; and to impartially enforce laws and ordinances such as parking and school zone regulations.

Police department offices are on the first floor of the borough's municipal building.