Big O or The Big O may refer to:
Mathematics and computing Big Omega function (disambiguation), various arithmetic functions in number theory Big O notation, asymptotic behavior in mathematics and computing Time complexity in computer science, whose functions are commonly expressed in big O notation
People Omar Gooding (born 1976), American actor, rapper, voice artist and comedian Oliver Miller (1970–2025), American professional basketball player Takashi Nagasaki (born 1958), Japanese author Barack Obama (born 1961), 44th President of the United States Roy Orbison (1936–1988), American singer-songwriter Glenn Ordway (born 1951), Boston-area sports radio host Otis Redding (1941–1967), American soul singer-songwriter and record producer Oscar Robertson (born 1938), former professional basketball player Oscar Santana, American radio personality Oprah Winfrey (born 1954), American television host, producer and philanthropist Oscar McInerney (born 1994), Australian rules footballer
Structures and venues Big O (Ferris wheel), the world's largest centerless Ferris wheel, in Japan Big "O", a structure on Skinner Butte in Eugene, Oregon, United States, listed on the National Register of Historic Places Olympic Stadium (Montreal), Quebec, Canada; the main venue of the 1976 Summer Olympics Ontario Motor Speedway, California, USA; former superspeedway racecar track
Other uses "The Big O", a name given to the Omaha–Council Bluffs metropolitan area The Big O, a 1999 Japanese animated TV series Omega (Ω), a Greek letter, whose name translates literally as "great O" Big O Tires, a tire retailer in the United States and Canada The Big O (album), by Roy Orbison Big Orange Chorus, a barbershop men's chorus in Jacksonville, Florida
See also Bigo (disambiguation)