Georgia O'Keeffe		Georgia O'Keeffe (November 15, 1887 - March 6, 1986) was an American artist.
Chris Ofili		Chris Ofili (born 1968) is an English born painter noted for artworks referencing aspects of his Nigerian heritage. He is one of the Young British Artists. He is a Turner Prize winner and his work has been a source of controversy.
Claes Oldenburg		Claes Oldenburg (born January 28, 1929) is a sculptor, best known for his public art installations typically featuring very large replicas of everyday objects. Another theme in his work is soft sculpture versions of everyday objects.
Jules Olitski		Jules Olitski (March 27, 1922 – February 4, 2007) was an American abstract painter, printmaker, and sculptor.
Francisco Oller		Francisco Manuel Oller Cestero (June 17, 1833 – May 17, 1917) was a Puerto Rican artist. Oller is considered to be the only Latin American painter to play a role in the development of Impressionism.
Yoko Ono		Yoko Ono Lennon (born February 18, 1933) is a Japanese artist and musician. She is known for her work as an avant-garde artist and musician and her marriage and works with English musician John Lennon. She currently lives in New York City.
Maria van Oosterwijck		Maria van Oosterwijck, (Aug 20, 1630, Nootdorp - Nov 12, 1693, Uitdam) was a Dutch Baroque painter, specializing in richly detailed still-lifes.
Jose Clemente Orozco		José Clemente Orozco (November 23, 1883 - September 7, 1949) was a famous Mexican social realist painter, who specialized in bold murals that established the Mexican Mural Renaissance together with murals by Diego Rivera, Siqueiros, and others.
Jean-Baptiste Oudry		Jean-Baptiste Oudry (17 March 1686, Paris - 30 April 1755, Beauvais) was a French Rococo painter, engraver and tapestry designer. He is particularly well known for his images of animals and his hunt pieces depicting game.