Santai County (simplified Chinese: 三台县; traditional Chinese: 三台縣; pinyin: Sāntái Xiàn; Wade–Giles: San1-t῾ai2 Hsien4; Sichuanese romanization: San1-t῾ai2 Shien4; formerly known as Tungchwanfu, Sichuanese romanization: Tongchuanfu) is a county under the administration of the prefecture-level city of Mianyang, in the northeast of Sichuan Province of China.

It has an area of 2,660.58 km2 (1,027.26 sq mi).

[1] Santai County comprises 31 towns and 2 townships:[2] During the late 19th and first half of 20th century, Tungchwan was one of the mission centres of the Friends' Foreign Mission Association (FFMA),[3] being the largest mission branch of FFMA's Northern District.

Quaker-affiliated hospital, meeting house, boys' school and girls' boarding school were built during this period.

[4] The British political economist and missionary Audrey Donnithorne was born at a Quaker hospital in Santai.