Stefan Ilchev (1898–1983) is a Bulgarian linguist. He was born on 29.09.1898 in the town of Botevgrad. He graduated from Slavic Philology at the Sofia University (1925). He studied in Warsaw, Krakow and Prague (1929–1930). He was a Senior Research Associate. He also worked at the Institute of Bulgarian Language at the Bulgarian Academy of Sciences. His collaboration in the writing of interpretations and spelling dictionaries has a huge impact to Bulgarian linguistics. Part of his studies are the books "Dictionary of the Personal and Surnames of the Bulgarians" (1969) and "Dictionary of Rare, Outdated and Dialectical Words in our 19th and 20th Centuries Literatures" (1974; 1998). Author of many articles. He died on March 4, 1983, in Sofia.