Roi Et is one of the provinces of Thailand, located in the North-East of Thailand. Neighboring Provinces are (from north clockwise) Kalasin, Mukdahan, Yasothon, Sisaket, Surin and Maha Sarakham. The Name Roi Et translates to 101, which refers to the original 11 satellite cities around the main city as well as the 11 city gates. To express the importance of the city the number was exaggerated.
Most part of the province is covered by plains about 130-160 meters above sea level, drained by the Chi River. In the north of the province are the hills of the Phu Phan mountain range, with the Yang River as the major river. In the south is the Mun River, which also forms the boundary to the province of Surin. At the mouth of the Chi River, where it enters the Mun River, a big flooded basin provides a good rice farming area.