Bogumil Vošnjak, also known as Bogomil Vošnjak (9 September 1882 – 18 June 1955), was a Slovene and Yugoslav jurist, politician, diplomat, author, and legal historian. He often wrote under the pseudonym Illyricus.
He was born as Bogomil Vošnjak in Celje, then part of the Austro-Hungarian Duchy of Styria, in the Slovene branch of the notable Styrian industrialist Vošnjak/Woschnagg family. His father Miha Vošnjak, native from Šoštanj, was one of the founders of liberal-progressive peasant cooperatives in Lower Styria. His uncle Josip Vošnjak, was the leader of the Slovene National Progressive Party in Lower Styria. He attended the elementary school in Celje and later in Graz, where he moved with his father. He later returned to Celje, where he enrolled to the First Celje Grammar School. In 1896 he moved to Gorizia, where he attended the Gorizia Grammar School, graduating in 1901. He then went to Vienna, where he studied law at the University of Vienna. After graduating in 1906, he continued his studies at the École Libre des Sciences Politiques in Paris and at the University of Heidelberg. In 1912, he got employed as a lecturer at the University of Zagreb. It was at this time that he started using the Croatian version of his name, Bogumil.