Police vehicles in Japan are vehicles used by Japanese prefectural police for patrolling, consisting of a variety of vehicles depending on the environment and situation. Most police vehicles in Japan are manufactured by domestic automakers such as Toyota, Nissan, or Subaru.

The formal Japanese term for a police vehicle is keirasha (警邏車), but the term patokā (パトカー), an abbreviation of "patrol car", is also widely used. The acronym "PC" is commonly used in police terminology (including over the radio).

Unlike how some departments in the U.S. and Canada allow their officers to take home their police vehicles, Japan does not allow officers to take home any kind of law enforcement vehicle. Every marked police car uses a black-and-white two tone livery, and police motorcycles are usually all white. Riot police vehicles are painted blue and white, and TMPD rescue vehicles are painted green and white.

Unlike fire trucks and ambulances, patrol cars often seen in the city are operated as mobile regional police units. They actively patrol the city to detect and prevent crimes and accidents rather than waiting at police stations, and are prepared to quickly arrive on scene whenever an emergency call is made. In addition, both traffic police and criminal police units do not only carry out police operations and investigations in the city, but also serve an operational purpose to quickly reach a scene from within the city.

The beginning of police cars in Japan is said to be at the Asakusa police station in January 1949 (Shōwa 24). Following post-WWII turmoil, security in Japan was poor, with many robberies and thefts. Therefore, the local municipal police at the time painted a US military-sourced car as a trial "mobile police" (移動警察, idō keisatsu) vehicle.

In June 1950 (Shōwa 25), the Tokyo Metropolitan Police Department deployed three so-called patrol cars, which were modified sedan-bodied WWII-era Nissan 180 truck chassis with radios. As the Korean War broke out at around the same time, the Japanese Red Purge became popular under the MacArthur Directive, and the role of the municipal police increased.

These first three police cars were of poor quality with a harsh ride, and broke down frequently. As a result, subsequent police cars were based on Ford and Chevrolet models sold by the US military. Due to a stated risk of radio jamming and interception, police radios were prohibited at the discretion of the Supreme Commander for the Allied Powers, so police cars often got lost. VHF radios were finally allowed from the late 1950s.

In the 1960s, when the quality of domestic cars began to rise, police cars also began to be based on new domestic models, such as the Toyota Crown-based Toyota Patrol. The Nissan Cedric and Isuzu Bellel were also adopted as base vehicles for police cars, and before long, only domestic models were used as police vehicles.