Thomas Johannes Obenhuber (born 1955)
Dr. John F. "Jack" Obijeski (born 1941)
Dr. Paul Allan Offit (born 1951)
Dr. Lloyd John Old (born 1933)
Kevin James Olival (born 1975)
Lionel Herbert Olmer (born 1934)
Kenneth Harry Olsen (born 1926)
Dr. Frank Rudolph Emmanuel Olson (born 1910)
Theodore Bevry Olson (born 1940)
Barbara Kay (Bracher) Olson (born 1955)