Koo may refer to:
- Kōō (Nanboku-chō period) (1389–1390), a Japanese era
- Koo Chen-fu (1917–2005), a Taiwanese businessman and diplomat
- Koo Chung, Korean American Christian singer-songwriter
- Koo Dae-Sung (born 1969), a South Korean Major League Baseball player
- Koo De Tah, a New Zealand/Australian pop music band of the 1980s
- Koo Hsien-jung (1866–1937), Taiwanese businessman and politician
- Koo Ki-Lan (born 1977), a South Korean volleyball player
- Koo Kien Keat (born 1985), a professional badminton player from Malaysia
- Koo Koo, the title of the debut solo album by Debbie Harry (August 1981)
- Koo-Koo the Bird Girl was born Minnie Woolsey in 1880 and suffered from Virchow-Seckel syndrome
- Koo Stark (born 1956), an American film actress and photographer
- Koo-Vee, a Finnish ice hockey team based at Tampere
- Koo Wee Rup, Victoria, a town in Australia, 70 km south-east of Melbourne
- Koo's Art Center, an art gallery and music venue in Long Beach, California, USA
- Koo-Vee (ice hockey), a Finnish ice hockey team based at Tampere
- Ku Hye Sun, a South Korean popular actress and singer
- KOO, a South African food brand
Other articles associated with the title Koo:
- Chung Mong Koo, (b. March 19, 1938 in Seoul) is the chairman of Hyundai Kia Automotive Group
- Dae-Sung Koo (born 1969), a left-handed pitcher for the Hanwha Eagles in the Korean Baseball Organization
- Duk Koo Kim (1959–1982), a South Korean boxer who died following a boxing match against Ray Mancini
- Fatty Koo, a R&B and Hip-Hop sextet from Columbus, Ohio
- Hitchy-Koo (1919), a musical revue with music and lyrics by Cole Porter
- House of Fatty Koo, debut album by Fatty Koo
- Jeffrey Koo Sr. (born 1933), Taiwanese banker
- Joseph Koo, MBE, SBS (born 1933), one of the most respected composers in Hong Kong
- Josephine Koo (Chinese: 顧美華) is a Chinese actress
- Jung Koo Chang (born 1963) is a South Korean world boxing champion
- Kaija Koo (born 1962), a Finnish singer
- Louis Koo, born 21 October 1970 in Hong Kong is a Chinese actor
- Nathan Koo-Boothe (born 1985), a Jamaican international footballer
- Ngeh Koo Ham (born 1961), member of the Democratic Action Party (DAP) in Malaysia
- Tai Koo (disambiguation)
- Tai Koo Shing Ferry Pier (1980–1983), a small-sized barge pier in Tai Koo Shing, Quarry Bay, Hong Kong
- Tai Koo Station, a station on the Island Line of the Hong Kong MTR system
- The Kim Koo Museum, a museum in Seoul, South Korea which commemorates the life and thoughts of Kim Koo, Korean independence activist against Japanese occupation of Korea
- Wellington Koo, a Chinese diplomat