The Co Tu (or Ca Tu, Ca Tang; Vietnamese: người Cơ Tu) are an ethnic group in Vietnam. Most Co Tu live in the provinces of Thừa Thiên -Huế and Quảng Nam. The population in Vietnam was 50,458 in the 1999 census and 61,588 in the 2009 census. They speak a language in the Mon–Khmer language family.
The Co Tu typically serve rice cooked in bamboo stems such as zăr, aví hor, koo dep, koo gdhoong, and cha chắc, and drink a beverage called tavak. Their famous dances are tung tung (performed by males) and ya yá (performed by females). They play h'roa in ordinary life. Traditional Co Tu homes are on stilts and those who live on the Laotian border are known for growing jute and weaving.