IV

IV as the Roman number for four may refer to:
*IV St. Albert 05-06 (Concepcion Catholic School IV-B section)
* "Led Zeppelin IV", the fourth album by Led Zeppelin containing the popular song "Stairway to Heaven"
* "Atomic Rooster IV", the U.S. release of Atomic Rooster's fifth album, "Nice 'n' Greasy"
* "IV" (Cypress Hill album), the fourth album of Cypress Hill
* "IV" (Diamond Rio album), a 1996 album by Diamond Rio
* "IV" (Faust album), also known as "Faust IV", the fourth album by Faust
* "IV" (Godsmack album), the fourth album of Godsmack
* "IV" (To/Die/For album), the fourth album of To/Die/For
* "IV" (Veruca Salt album), the fourth album by Veruca Salt
* "IV" (Winger album), an album of Winger
* I.V., X Japan song
* "Toto IV", the fourth album of the band Toto
* "Grand Theft Auto IV, a video game that was referred to simply as "IV" by the developers before its release

IV as an acronym may refer to:
* Current-voltage in electronics where I=current and V=voltage
* Côte d'Ivoire, from the NATO country code
* Immigration voice a non-profit organisation working to alleviate problems faced by legal high-skilled foreign workers in the United States.
* Implied volatility in financial mathematics
* Independent verification systems, voting machines
* Industrievereinigung, Federation of Austrian Industry
* Initialization vector, a nonsecret binary vector in cryptography
* Instrumental variable, a statistical analysis method
* Inter vivos trust, a living trust created during a person's lifetime
* "International Viewpoint", the monthly magazine of the Reunified Fourth International
* InterVarsity Christian Fellowship, a Christian ministry for college students
* Intravenous therapy, giving of a liquid substance directly into a vein
* IrfanView, a freeware image viewer
* Irish Volunteers, a historical organisation from Ireland.
* Isla Vista, an unincorporated community in Santa Barbara County, California, US