Orlando Furioso (The Frenzy of Orlando, more literally Mad Orlando; in Italian furioso is seldom capitalized) is an Italian epic poem by Ludovico Ariosto which has exerted a wide influence on later culture. The earliest version appeared in 1516, although the poem was not published in its complete form until 1532.

The poem is divided into forty-six cantos, each containing a variable number of eight-line stanzas in ottava rima (a rhyme scheme of abababcc). Ottava rima had been used in previous Italian romantic epics, including Luigi Pulci's Morgante and Boiardo's Orlando Innamorato. Ariosto's work is 38,736 lines long in total, making it one of the longest poems in European literature.