Oscar can refer to

• A nickname for an Academy Award.
• A common name for Astronotus ocellatus, a species of aquarium fish. See Oscar (fish).
• The letter O in the NATO phonetic alphabet
• Oscar the Grouch is the name of a muppet on Sesame Street.
• Oscar I - king of Sweden and Norway
• Oscar II - king of Sweden and Norway
• Prince Oscar, Duke of Gotlandia - prince of Sweden and Norway, later Count Bernadotte af Wisborg
• King Oscar sardines - a sardine brand
• Oscar (1967 movie) is an acclaimed comedy starring Louis de Funès
• Oscar (1991 movie) is a remake of the 1967 film, starring Sylvester Stallone
• The OSCAR protocol, as used by the AOL Instant Messenger service.
• The Oscar class submarine, built by the Soviet Union.
• OSCAR (Orbiting Satellite Carrying Amateur Radio) is a series of communications satellites built and used by amateur radio operators.
• Oscar , full name José Oscar Bernardi, Brazilian football (soccer) player
• Old Oscar is a character in the Jay Jay the Jet Plane children's story series.