DEV Oskar (2.XII.1868, Planina na Notranjskem - 3.VIII.1932, Maribor) was a Slovenian jurist, composer and choir conductor.
Musically, he was already influenced by composer-priest Hugolin Sattner at the high school in Novo mesto. From 1885 to 1888 he attended the Glasbena matica School of Music in Ljubljana and the church music school "Ambrosiusverein" in Vienna (1888-90) under the direction of Julius Bohm. He graduated from law in Vienna (1897). During his studies in Vienna, he was the conductor of the Slovenian Society and the Slovenian Singing Society.
After graduation he worked as a judge in Škofja Loka (1905-1911), Kranj and Maribor (1919-1932), where he most recently served as a Regional Judicial Councilor. Here in 1919 he founded the Glasbena matica Maribor Music Organisation, of which he was for many years president and choir conductor, as well as a number of choirs and a music school.
He has composed several songs for male and mixed choirs and vocal songs with piano accompaniment (in Glasbena Matica and Novi akordi). He collected and harmonized folk songs, including about 400 Carinthian songs. The national songs adapted from it were published partly by Schwentner in Ljubljana, partly by the Ljubljana Glasbena matica.