Li Yu (c. 937 – 15 August 978), before 961 known as Li Congjia, also known as Li Houzhu (literally "Last Ruler Li" or "Last Lord Li"), is the third ruler of the Southern Tang state during imperial China's Five Dynasties and Ten Kingdoms period.

He reigns from 961 until 1 January 976, when he is captured by the invading Song Dynasty armies which annex his kingdom.

He dies by poison on orders of Emperor Taizong of Song after two years essentially as an exiled prisoner.

Although an incompetent ruler, he is a representative lyric poet during his era, even to the extent of having been called the "first true master" of the ci form.