The Matsu Islands ( ) are a minor archipelago of 19 islands and islets in the Taiwan Strait administered as Lienchiang County (連江 Pinyin: Liánjiāng), Fukien Province of the Republic of China (ROC). Not all of what is historically part of Lienchiang county is under the control of the ROC. The People's Republic of China controls the part of the county adjoining the mainland and has a separate administration for that jurisdiction, Lianjiang County, which claims the entire archipelago to be its Mazu Township (媽祖鄉).

They are named after the goddess Matsu. Kinmen is the other archipelago on the Fujian coast controlled by the ROC.