Theodosius Grygorovych Dobzhansky (Ukrainian: Теодо́сій Григо́рович Добжа́нський; Russian: Феодо́сий Григо́рьевич Добржа́нский; January 25, 1900 – December 18, 1975) was a prominent Ukrainian-American geneticist and evolutionary biologist, and a central figure in the field of evolutionary biology for his work in shaping the modern synthesis. Dobzhansky was born in Ukraine, then part of the Russian Empire, and became an immigrant to the United States in 1927, aged 27.

Theodosius (Latinized from the Greek "Θεοδόσιος", Theodosios, "given by god") is a given name. It may take the form Teodósio, Teodosie, Teodosije etc.

Saint Theodosius of Manyava (Ukrainian: Феодосій Манявський, died 24 September 1629 in Manyava Skete, Ukraine ) is a Ukrainian Orthodox saint, venerable, ascetic and one of the founders and the second hegumen (abbot) of Manyava Skete, men's cell solitary monastery in the Carpathian Mountains of western Ukraine.

Theodosius VI (Abourjaily) of Antioch was Greek Orthodox Patriarch of Antioch from 1958 to 1970.

Theodosius II (Greek: Θεοδόσιος Β΄), lay surname Christianopoulos (Χριστιανόπουλος) served as Ecumenical Patriarch of Constantinople during the period 1769-1773.