Maureen O'Hara
John O'Neil
Francis O’Donnell
Barbara Oakley
Nobuaki Oda
Shigeru Oda
Eric Odada
Nduka Okafor
Rogers Okot-Uma
H. W. O. Okoth Ogendo
Ingram Olkin
Aftab Omer
Ruth Oniang'o
Georgi Oniani
Yasuaki Onuma
Yuri Osipov
John Oucho
Yao Ouyang