Woo, WoO, WOO, W.O.O. and variants may refer to:

Woo or Wu, romanization of several East Asian names:

• Hu (surname): 胡, 瓠, 護, 戶, 扈, 虎, 呼, 忽, 斛
• Wu (surname): 吳, 伍, 武, 仵, 烏, 鄔, 巫
• Ng (name): 吳, 伍
• Woo (Korean name), a Korean surname and given name: 우
• Woo, Łukasz Obrzut, nickname of Polish-American basketball player based on the pronunciation of his first name (Woo-kosh)

• Woo (film), a 2020 romantic comedy
• "Woooo!", a 2008 television episode of How I Met Your Mother
• Woo, a character in the King of the Monsters series of video games
• WoO, an alien creature in Bio Planet WoO, a Japanese television show
• Woo, a fictional monster in the Ultraman television series
• Woo, a character in the movie The Big Lebowski
• Woo, or WoO, also known as WWOO WWoO, abbreviation for The Wizard of Oz
• "Woooo!", a catchphrase by pro wrestler Ric Flair

• WoO, ("Works without opus number"), a cataloging system for Beethoven's (and some other composers') works
• Woo (music group), a British experimental band
• Woo (soundtrack), a soundtrack album from the 1998 film
• "The Woo", a song by Pop Smoke
• "Woo", a song by Rihanna from Anti
• Woo!, a 2003 EP by Tilly and the Wall

• College of Wooster
• World of Outlaws, a car racing organization
• WOO (Philadelphia), a broadcasting station which operated from 1922 to 1928
• The callsign WOO, used by the AT&T High Seas Service transmitter station in Ocean Gate, New Jersey
• Woo, a derogatory term for pseudoscience and other non-evidence-based beliefs.
• Courtship, also known as "wooing"

• Woo Hoo (disambiguation)
• Woo Woo (disambiguation)
• Wu (disambiguation)
• Woo! Yeah!