Bairi (Tianzhu) Tibetan Autonomous County (Tibetan: དཔའ་རིས་བོད་རིགས་རང་སྐྱོང་རྫོང༌།, Wylie: dpa'a-ris bod-rigs rang-skyong rdzong/, ZYPY: Bairi Poirig Ranggyong Zong; Chinese: 天祝藏族自治县; pinyin: Tiānzhù Zàngzú Zìzhìxiàn) is in the prefecture-level city of Wuwei in the Chinese province of Gansu. It has an area of 7,147km² and approximately 230,000 inhabitants (2003). Its administrative seat is the town of Huazangsi.
Lanzhou–Xinjiang Railway crosses the county, with a station (Tianzhu) in the county seat. With the construction of the Wushaoling Tunnel under the Wushao Mountain Range (Wushaoling), about the half of the section of the main track of this railway within this county is actually underground.