The Royal Thai Police (RTP) is the national police force of Thailand. The RTP employs between 210,700 and 230,000 officers, roughly 17 percent of all civil servants. The RTP is frequently recognized as the fourth armed force of Thailand since their tradition, concept, culture, skill, and training are relatively similar to the army and most of their officer cadets need to graduate from the Armed Forces Academies Preparatory School before entering the Royal Thai Police Cadet Academy. Officers also undergo paramilitary training similar to the army but with an additional focus on law enforcement.

The Armed Forces Academies Preparatory School or AFAPS is a senior high school in Nakhon Nayok Province. It is a flagship institution of the Royal Thai Armed Forces Headquarters. The curriculum consists of academic and physical training as well as other activities. Cadets who manage to graduate automatically gain entrance to the Chulachomklao Royal Military Academy, the Royal Thai Naval Academy, the Royal Thai Air Force Academy, or the Royal Thai Police Academy.