Emergency service response codes are predefined systems used by emergency services to describe the priority and response assigned to calls for service. Response codes vary from country to country, jurisdiction to jurisdiction, and even agency to agency, with different methods used to categorize responses to reported events.

Emergency services and rescue services are organizations that ensure public safety, security, and health by addressing and resolving different emergencies. Some of these agencies exist solely for addressing certain types of emergencies, while others deal with ad hoc emergencies as part of their normal responsibilities. Many of these agencies engage in community awareness and prevention programs to help the public avoid, detect, and report emergencies effectively. Emergency services are often considered first responders, and typically have dedicated emergency vehicles.