Mauša Ordmanas (?–1942)
J. Orechov
Gediminas Orentas (1915-02-14–2007-02-07)
Emilis Orestrupas (1800-12-04–1856-07-21)
Carl Orff (1895-07-10–1982-03-29)
Maurycy Orgelbrand (1826–1904)
Petronėlė Orintaitė (1905-02-18–1999-12-16)
Antanas Orintas
Jonas Orintas (g. ~1902)
Pranas Orintas
Juozas Orlauskis (1887-10-17–1970-07-07)
J. Orlikas
Emil Orlík (1870-07-21–1932-09-28)
Viktor Orlov (1928–1972)
Vera Orlova (1918-05-25–1993-09-16)
Vladimiras Orlovskis (1842–1914)
Angelė Orlovskytė (1955–2014)
Roman Orłow (1922–2017)
Aleksander Orłowski (1777-03-09–1832-03-13)
Alfredas Orsė (1801–1852)
Abrahamas Ortelijus (1527-04-04–1598-06-26)
Diego Ortiz (1510–1576)
Andrius Orvidas
Ignotas Orvidas
Jonas Orvidas (1875–1942)
Jonas Orvidas (1875–1939)
Vilius Orvidas (1952-08-18–1992-08-05)
Tadas Orvydas
Emilija Orvidienė (1908-08-15–1963-08-22)
Sofija Orvidova Antanovičiova
George Orwell (1903–1950)
Eliza Orzeszkowa (1841–1910)
Einaras Osas (g. 1926)
A. Oseckij
Ivaras Osenas (1813-08-05–1896-09-23)
Nikolajus Osenevas (1909–1983)
Wiesław Osewski (1949–2018)
A. Osiecimski
Taisija Osinceva (1923-10-09–2008-11-17)
Zigmuntas Osipo Gruževskis
Osipov
N. Osipovskij
Aleksandras Osmiorkinas (1892-12-08–1953-06-25)
Povilas Osmolskis (1919-05-17–1971-03-17)
Wilk Ossecki (1892–1958)
J. H. Ossowski
Adrianas Ostadė (1610–1685)
Viktoras Ostašenkovas (1943-11-28–2012-10-31)
Marie Ostermeyer
Osterwald
Kostas Ostrauskas (1926-04-05–2012-01-09)
Mečislovas Ostrauskas (1927-01-17–2002-01-07)
Tomas Ostrauskas (g. XIX a.)
Valerija Ostrauskienė (1927-10-29–1997-08-11)
Hermanas Ostrichas (1903–1973)
Aleksandr Ostrogorskij (1868–1908)
Ilja Ostrouchov (1858–1929)
Ana Ostroumova-Lebedeva (1871-05-17–1955-05-05)
Arkadij Ostrovskij (1914–1967)
Nikolaj Ostrovskij (1904-09-29–1936-12-22)