Karl Wilhelm Friedrich (after 1814: von) Schlegel (/ˈʃleɪɡəl/ SHLAY-gəl; German: [ˈfʁiːdʁɪç ˈʃleːɡl̩]; 10 March 1772 – 12 January 1829) was a German literary critic, philosopher, and Indologist. With his older brother, August Wilhelm Schlegel, he was one of the main figures of Jena Romanticism.
Born into a fervently Protestant family, Schlegel rejected religion as a young man in favor of atheism and individualism. He entered university to study law but instead focused on classical literature. He began a career as a writer and lecturer, and founded journals such as Athenaeum. In 1808, Schlegel returned to Christianity as a married man with both him and his wife being baptized into the Catholic Church. This conversion ultimately led to his estrangement from family and old friends. He moved to Austria in 1809, where he became a diplomat and journalist in service of Klemens von Metternich, the Foreign Minister of the Austrian Empire. Schlegel died in 1829, at the age of 56.