Nakhon Ratchasima (Thai: นครราชสีมา), often called by the nickname Khorat (โคราช), is one of the North-East provinces (changwat) of Thailand. Neighboring provinces are (clockwise, from north) Chaiyaphum, Khon Kaen, Buriram, Sa Kaeo, Prachinburi, Nakhon Nayok, Saraburi, Lopburi.
The capital of the province is the city of Nakhon Ratchasima located in Mueang Nakhon Ratchasima District, also called Khorat. The Khmer name for the province is Nokor Reach Seima, the Malay name is Negara Raja Sima.