UU

UU or uu may refer to:

Businesses

 * United Utilities (LSE stock symbol UU)
 * Air Austral (IATA airline code UU)

Language

 * "uu", an old way of spelling the letter "w" in certain Germanic languages, including Old English
 * The letter combination of uu

Science and technology

 * UUNET, Internet Service Provider commonly referred to as 'UU'
 * Unique users, may be counted as part of web analytics in determining the popularity of a website
 * UMTS air interface or "Uu interface", which links User Equipment to the UMTS Terrestrial Radio Access Network
 * Unix-to-Unix, as in uuencode, a data transport encoding
 * .uu, a compressed archive file extension, associated with uuencode

Universities

 * Ulster University in Northern Ireland
 * Union University in Jackson, Tennessee, United States
 * University of Utah in Salt Lake City, Utah, United States
 * Uppsala University in Sweden
 * Utica University in Utica, New York, United States
 * Utrecht University in the Netherlands
 * Uttaranchal University in Uttarakhand, India

Other uses

 * Union of Utrecht (Old Catholic), a federation of Old Catholic churches
 * Unitarian Universalism, a theologically liberal religion characterized by its support for a "free and responsible search for truth and meaning."
 * Unseen University, in the fictional Discworld novels of Terry Pratchett


 * UU, the production code for the 1968 Doctor Who serial The Mind Robber
 * U'u a war club from Marquesas Islands
 * Undead Unluck a shorthand for the manga by Yoshifumi Tozuka.