Zuojiang Zhuang(Chinese:左江壮语) is the various Zhuang languages spoken along the Zoujiang River, including in Guangxi the counties of Tiandeng, Daxin, Chongzuo, Ningming, Longzhou, and Pingxiang  some villages in Funing Yunan, and Vietnam, and is a putative branch of Tai languages of China and Vietnam. Also known as Tho (a name shared with Tày and Cuoi of Vietnam).
In the 1950s as part of the classification of Zhuang languages, Zuojiang Zhuang was recognised as a dialect, or language, in Guangxi, China. In 2007, ISO 639-3 also included speakers Vietnam as the Zuojiang river goes into there. In the classification of Phittiyaporn (2009), suggests Zuojiang is not a single language, but part of two main branches of the Tai language family (clades B, F, and H). See Tai languages for details.