The Volunteer Defense Corps (Thai: กองอาสารักษาดินแดน; abbreviated VDC) is a paramilitary under the authority of the Department of Provincial Administration (DOPA), Ministry of Interior.

[1] It was founded in 1954 to provide extra military support to the Royal Thai Armed Forces and to protect local civilians living near Thailand's borders.

[2][3] The Volunteer Defense Corps (colloquially called Or Sor in Thailand) was formally established on 10 February 1954[4][3] by the Thai Border Patrol Police (BPP) in response to complaints by civilians of banditry and harassment by insurgent and separatist organizations.

Originally, the VDC's purpose was to protect civilians from insurgents who had crossed into Thai border provinces from neighboring Cambodia, Laos and Malaysia.

[5] In 1974, the VDC was expanded by the Internal Security Operations Command (ISOC) to urban areas to fight communist insurgents.