DNA confirmed people with O surname

• John Aloysius O'Brien ( - 1937)
• Florence O'Brien ( - 1967)
• Cecelia Bernice Veronica O'Brien (1903 - 1996)
• M Oosterink (1932 - 2015)
• Anton Oquist (1840 - )
• Harry Anton Oquist (1888 - 1942)
• Ellen Harriet Oquist (1914 - 2011)
• Ellen OSullivan
• Michael OSullivan