IU may refer to:
The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List), founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species.
Lee Ji-eun (Korean: 이지은; born May 16, 1993), better known by her stage name IU (Korean: 아이유), is a South Korean singer, songwriter and actress.
In chemical nomenclature, the IUPAC nomenclature of organic chemistry is a systematic method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC).
Intrauterine device (IUD) with copper also known as intrauterine coil, is a type of intrauterine device which contains copper.
Intrauterine device (IUD) with progestogen, sold under the brand name Mirena among others, is a intrauterine device that releases the hormone levonorgestrel.
The IUCN Species Survival Commission is a special commission operated by the International Union for Conservation of Nature.
On 29 January 2010, the IUCN Red List of Threatened Species identified 842 (746 animals, 96 plants) extinct species, subspecies and varieties, stocks and sub-populations.
The discography of South Korean singer-songwriter and actress IU consists of three studio albums, nine extended plays (EPs), 35 singles, and 37 music videos.
The Indiana University of Pennsylvania Crimson Hawks, commonly known as the IUP Crimson Hawks and formerly called the IUP Indians are the varsity athletic teams that represent Indiana University of Pennsylvania.