The Ơ Đu (O'du) are an aboriginal ethnic group in Vietnam and Laos. Their total population is more than 570.

The Ơ Đu are also commonly referred to as O'Du, O Du, Iduh, Tay Hat, Hat, and Haat.^[2]

The Ơ Đu subsist mainly on slash-and-burn agriculture and raising cattle, augmented by hunting, gathering, and weaving.

The Ơ Đu have a language also called O'du, which is a Khmuic language.^[2] The Khmuic languages are Austro-Asiatic.^[2] There is some debate as to whether the Khmuic languages are of the Mon–Khmer branch, but the majority opinion is that they are not. Most Ơ Đu presently speak Thai.^{[citation needed]}

• Population in Laos: 194 in Xiangkhouang Province^[2]
• Population in Vietnam: 301 in Tương Dương district of the Nghệ An Province (North Central Coast region)

• List of ethnic groups in Vietnam
• List of ethnic groups in Laos

• http://projekt.ht.lu.se/rwaai RWAAI (Repository and Workspace for Austroasiatic Intangible Heritage)
• http://hdl.handle.net/10050/00-0000-0000-0003-93EF-1@view Iduh in RWAAI Digital Archive