Military police (MP) are law enforcement agencies connected with, or part of, the military of a state. In wartime operations, the military police may support the main fighting force with force protection, convoy security, screening, rear military reconnaissance, logistic traffic management, counterinsurgency, and detainee handling.

In different countries it may refer to:

• A section of military forces assigned to police, or garrison, occupied territories, usually during a war.
• A section of military forces assigned to policing Prisoner of war detentions.
• A section of the military responsible for policing the areas of responsibility of the armed forces (referred to as provosts) against all criminal activity by military or civilian personnel
• A section of the military responsible for policing in both the armed forces and in the civilian population (most gendarmeries, such as the French Gendarmerie or the Spanish Guardia Civil)
• A section of the military solely responsible for policing the civilian population (such as the Romanian Gendarmerie or the Chilean Carabineros)
• The preventive police forces of each Brazilian state (Polícia Militar), responsible for policing the civilian population, which are reserve forces of the Brazilian Army and can be pressed into federal service during times of war

The status of military police is usually prominently displayed on the helmet, with an armband, brassard, or arm or shoulder flash. Military police personnel may also wear a more traditional police badge, usually on the front of their uniform; They may also wear other accoutrements exclusive to military police personnel.

Naval police personnel are sometimes called "masters-at-arms" and/or "shore patrol". Law enforcement personnel of an air force are sometimes called "air police", "security police" or "security forces".