If you are talking about first names, here are several I've come up with:
Oliver Stone - Director
Oliver Hardy - Comic
Olivia de Havilland - Actress
Olivia Newton-John - Singer
Oscar Hammerstein - Composer
Olivia Hussey - Actress
Oscar Wilde - Author
Omar Bradley - American general
Olive Oyl - Cartoon character Popeye's wife
Orson Welles - Director, Writer, etc.
Orson Bean - Actor
Oscar de la Renta - Fashion Designer
If you are talking about people with the last name starting with O, here's some I came up with:
Pat O'Brien
John O'Hurley
Ryan O'Neal
Marie Osmond
Donny Osmond
Sir Laurence Olivier
Julia Ormond
Merlin Olsen
Mary-Kate Olsen
Ashley Olsen
Chris O'Donnell
The Oakland Athletics are a Major League Baseball team. The Oakland Raiders are a team in the National Football League. The Oklahoma City Thunder and the Orlando Magic are teams in the National Basketball Association. The Ottawa Senators are a team in the National Hockey League.
· O.J. Simpson (football)
· Oscar De La Hoya (boxer)
· Oscar Robertson (Basketball)
· Otto Graham (football)
· Merlin Olsen (football)
· Shaquille O'Neal (basketball)
· Bobby Orr (hockey)
· Mel Ott (baseball)
· Jesse Owens (athlete)
Kathern Hepburn
Bill Haley and the Comets the Happenings Heart Herman's Hermits
Leonardo Di Vinci. : P
Christopher Columbus
There are a few actors whose name begins with an X. Some of them include Xzibit, Xander Barkley, Xavier Samuel, Xavier Dolan, and Xenia Seeberg.
Youma thurman
Xenops
zoey
Angelina Jolie.
ghandi!
Hitler
yossien
Billy Madison
Ziggy Marley
Nicole kidman
Sarah paxton
drake bell