The Yao nationality (its great majority branch is also known as Mien; Pinyin: Y醥 z? Vietnamese: ngu?i Dao) is a government classification for various minorities in China. They form one of the 55 ethnic minority groups officially recognized by the People's Republic of China; where they reside in the mountainous terrain of the southwest and south.

They also form one of the 54 ethnic groups officially recognized by Vietnam. In the last census; they numbered 2;637;421 in China; and roughly 470;000 in Vietnam. In Thailand they number 40;000 and in Laos 20;000.