Santai County is a county located in the northeast of Sichuan Province, China. It operates under the administration of the prefecture-level city of Mianyang. The county covers a total area of 2,660.58 square kilometers (1,027.26 square miles).
As of early 2025, the resident population of Santai County is approximately 944,000, with an urbanization rate of 34.14%. The urban population is recorded at 322,300, while the registered population stands at 1,334,500.