OO or oo may refer to:
Udagamandalam (also known as Ootacamund (listen )), and abbreviated as Udhagai and popularly known as Ooty, (listen is a town and a municipality in the Indian State of Tamil Nadu.
Oops!... I Did It Again is the second studio album by American singer Britney Spears. It was released on May 16, 2000 in the United States through Jive Records.
Oobi is an American children's television series created by Josh Selig of Little Airplane Productions.
Oopiri (lit. Breath) is a 2016 Indian comedy-drama film directed by Vamsi Paidipally. A remake of Olivier Nakache & Éric Toledano's French comedy-drama The Intouchables (2011), the film was produced by Prasad V.
The Oort cloud (), named after the Dutch astronomer Jan Oort, sometimes called the Öpik–Oort cloud, is a theoretical cloud of predominantly icy planetesimals proposed to surround the Sun at distances ranging from 2,000 to 200,000 AU (0.03 to 3.2 light-years).
Oophorectomy (from Greek ᾠοφόρος, ōophóros, 'egg-bearing' + ἐκτομή, ektomḗ, 'a cutting out of') is the surgical removal of an ovary or ovaries.
"Oops!... I Did It Again" is a song by American singer Britney Spears, from her second album of the same name.
Oogenesis, ovogenesis, or oögenesis is the differentiation of the ovum (egg cell) into a cell competent to further develop when fertilized.
Oona O'Neill Chaplin, Lady Chaplin (14 May 1925 – 27 September 1991) was an actress who became a British citizen after renouncing her American citizenship.