• An onomatopoeia imitating the sound made by a cow
• Molly Moo-Cow, an animated character dating from the 1930s
• Moo (Monster Ranchers), a fictional character in the Monster Rancher anime
• Moo Who?, a 2004 children's book written by Margie Palatini
• Mr. Brown Can Moo! Can You?, a 1970 children's book by Dr. Seuss
• Why Cows Moo, a 1936 children's book by John Mystery
• Moo (novel), by Jane Smiley
• Moo (play) Floyd S. Chalmers Canadian Play Award winner by Sally Clark (playwright)

Computing:

• MOO, a type of MUD text-based virtual reality system, as in
• MOO programming language
• Moo Mapper, an editor for the IPL file format used for maps in Grand Theft Auto
• Moo.fx, a JavaScript effects library based on Prototype Javascript Framework

Food:

• Moo goo gai pan, a pseudo-Chinese American dish based on the Beef dish "mah gu gai pinku"
• Moo shu pork, a pseudo-Chinese dish served in Chinese restaurants in the United States
• Maggie Moo's, a chain of franchised ice cream restaurants based in Columbia, Maryland
• Moo & Oink, a Chicago-based grocery store chain that caters to the inner-city community

Martial arts:

• Hoi Jeon Moo Sool, a form of Korean martial arts that uses circular motions
• Moo Duk Kwan, a distinct school of Korean martial arts
• Sin Moo Hapkido, a martial art that combines "hard" and "soft" techniques
• Song Moo Kwan, the Ever Youthful House Of Martial Arts Training
• Han Moo Kwan founded in 1954 by Kyo Yun Lee
• Chang Moo Kwan founded by Yoon, Byung In and Lee, Nam Suk in 1946
• Yun Moo Kwan founded by Sang Sup Chun in 1946

Acronym:

• Mate of Origin, a rugby league tournament played annually between Australians and New Zealanders
• Master of Orion, a computer game
• Mothers Opposed to the Occult, a fictional organization from the episode Gingerbread of the television program Buffy the Vampire Slayer
• Melody of Oblivion, an anime
• Mode of operation, e.g. in cryptography

Person's name:

• Douglas J. Moo, a New Testament scholar
• Eric Moo, singer, composer
• Joong-Moo, given name to Admiral Yi Sun-Sin of the Yi Dynasty
• Lee Jang-Moo, professor of Mechanical Engineering in Seoul National University
• Moo Ko-Suen, a covert agent of the People's Republic of China who tried to purchase US military equipment
• Moo-Young Han (born 1934), professor of physics at Duke University
• Roh Moo-hyun (born 1946), President of South Korea since 2003

Gaming

• Moos are the common enemies in the Klonoa game series

Other uses:

• Muban, a Thai language word for "village group"