Osip Arkadyevich Yermansky, born Yosif Arkadyevich Kogan, and known by the pseudonyms M. Borisov, A. O. Gushka, Meerovich, and P. R., was a Russian Social Democratic political figure, economic theorist, pamphleteer, and memoirist. He was one of the originators of the Soviet school of management, in particular, its psychophysiological tendency. He regarded scientific management as a syncretic, interdisciplinary system, drawing material from other scientific disciplines, such as technology, economics, psychology, and physiology.

Oscar Becker was a German philosopher, logician, mathematician, and historian of mathematics.

Oskar Begas was a German portrait and history painter.

Oskar Bie was a German art historian and author of Jewish origin.

Oskar Davičo was a Serbian and Yugoslavian novelist and poet. A leading literary figure of his generation, he was one of the most acclaimed Serbian surrealist writers, but also a revolutionary socialist activist and a politician. Davičo was awarded prestigious literary NIN Award a record three times.

Oskar Halecki was a Polish historian, social and Catholic activist.

Henryk Oskar Kolberg was a Polish ethnographer, folklorist, and composer active during the foreign Partitions of Poland.

Oskar Kraus was a Czech philosopher and jurist.

Oskar Aleksandrovich Kuchera is a Russian actor, TV presenter and radio host. He was born in Moscow. He has made appearances in movies such as Unreal Love and Soldiers and is a presenter on Top Gear Russia.

Oskar Loerke was a German poet, prose writer, literary critic and essayist. Loerke was a prominent representative of Expressionism and magic realism in Germany.