Sergey Oleynikov (1919–2004) – a sworn advocate. >>

Afanasy Ordin-Nasсhokin (1605–1680) – a Russian diplomat and politician in the reign of Alexey Mikhailovich.  Russian vaivode of Koknese (Kokenhusen). >>

Leonid Orekhov (1930–2007) –  Doctor of Engineriing (Dr. sc. ing.), Docent of the Riga Technical University. >>

Mikhail Orlov (1918-1944) – the Great Patriotic War (World War II) Participant, Hero of the Soviet Union. Born in Latgale (East Latvia). >>

Oleg Orlov (1947)  – a vocalist, tenor, soloist of the Latvian National Opera, soloist of the Tallinn National Opera, soloist of the Krakow Philharmonic, vocal teacher at the Latvian National Opera. >>

Nina Orlova (1894-1980) –  a teacher of Russian language. >>

Zoya Orlova (1924-2005) – a Chief Physician of the Riga City 1st Clinical Emergency Hospital (1st Riga City Hospital) from 1972 to 1994. >>

Alexander Orlovsky (1867–1944) – a teacher of Russian language and literature, Headmaster of Riga 9^th Russian Elementary school. >>

Alexander Osadchy (1991) – a ballet dancer, soloist of the ballet troupe of the Latvian National Opera and Ballet. >>

Eugenia Oshurkova (1951) – a bard and journalist. >>