An IOU is an acknowledgment of debt.
IOU may also refer to:
Music I.O.U. (album), album by British jazz fusion guitarist Allan Holdsworth, 1982 I.O.U., album by Gregory Isaacs, 1982 "I.O.U." (Freeez song), 1983 "I.O.U." (Jimmy Dean song), 1976 "I.O.U." (Mike Shinoda song), 2018 "I.O.U." (Lee Greenwood song), 1983 "IOU", 2022 song by Five Finger Death Punch from AfterLife "I.O.U", 2020 song by NCT from NCT 2020 Resonance Pt. 2 I.O.U. (hip hop group)
Organizations Investor-owned utility, a supplier of basic services Intercultural Open University Foundation, a distance education institution Islamic Online University, an online, distance-learning university founded by Bilal Philips International Ornithologists' Union, new name of the International Ornithological Committee
Other uses Interdependent Occupational Unit, the monetary unit of the Kingdom of Lovely in the British television series How to Start Your Own Country GURPS Illuminati University, a sourcebook for the GURPS role-playing game Intersection over union, a measure for the similarity of two sets, which is also known as Jaccard index
See also IOYOU, former name of the Irish pop vocal group Westlife I Owe You, debut studio album by American contemporary gospel singer Kierra "Kiki" Sheard AEIOU (disambiguation)