Pi Rixiu (; ca. 834 – 883) was a Tang dynasty poet. His courtesy names were Yishao () and Ximei (), and he wrote under the pen name Lumenzi (). Pi was a contemporary of poet Lu Guimeng; these two poets are often referred to as Pi-Lu.
Pi was born at Jingling, Xiangyang (present-day Tianmen, Hubei Province). He is thought to have been of humble birth. He spent his youth traveling and writing: his verse was well known by the time he sat for the civil service examination, obtaining a degree of Jinshi in 867. He travelled to Suzhou in 868, where he became acquainted with Lu Guimeng. The subsequent correspondence of poems between the two would be collected by Pi in his Songling Ji (松陵集), one of his major works along with the Pizi Wensou (皮子文薮), whose matched rhyme poetry would later influence the poets of the Song Dynasty. Later, he was involved in the rebellion of Huang Chao.