A fire department (North American English) or fire brigade (Commonwealth English), also known as a fire authority, fire district, fire and rescue, or fire service in some areas, is an organization that provides fire prevention and fire suppression services.

Fire departments are most commonly a public sector organization that operate within a municipality, county, state, nation, or special district. Private and specialist firefighting organizations also exist, such as those for aircraft rescue and firefighting.

A fire department contains one or more fire stations within its boundaries, and may be staffed by firefighters, who may be professional, volunteers, conscripts, or on-call. Combination fire departments employ a mix of professional and volunteer firefighters. In some countries, fire departments may also run an ambulance service, staffed by volunteer or professional EMS personnel.