Annan (Chinese: 安南; pinyin: Ānnán; Vietnamese: An Nam; lit. 'pacified south') was an imperial protectorate and the southernmost administrative division of the Tang dynasty and Wu Zhou dynasty of China from 679 to 866, located in modern-day Vietnam. An Nam, simplified to "Annam", is the Vietnamese form of the Chinese name Annan, which means "the Pacified South" or "to pacify the South", a clipped form of the full name, the "Protectorate General to Pacify the South" (Chinese: 安南都護府; pinyin: Ānnán Dūhùfǔ; Vietnamese: An Nam đô hộ phủ).
In 679, the Annan Protectorate replaced the Jiaozhou Protectorate (Chinese: 交州; pinyin: Jiāozhōu) (Chinese: 交趾; pinyin: Jiāozhǐ; Vietnamese: Giao Chỉ), also known as Jiaozhi, with its seat situated in Songping County (宋平縣) (modern Hanoi). Annan was renamed to Zhennan for a brief period from 757 to 760 before reverting to Annan.
After coming under attack by Nanzhao in 864, the Annan Protectorate was renamed Jinghai Military Command upon its reconquest by Gao Pian in 866. Today the same area is sometimes known as Tonkin (Chinese: 東京; pinyin: Dōngjīng; Vietnamese: Đông Kinh), the "eastern capital" of Đại Việt. Locally, the area is known as Bắc Kỳ (北圻), the "northern area".