Claudia Cassidy (1899–1996), born in Shawneetown, Illinois, was a music, dance, and drama critic. She was so well known for giving caustic reviews to what she considered bad performances that she earned the nickname "Acidy Cassidy." Her judgment, however, which was regarded as extremely controversial even in her heyday, has been seriously doubted by more recent critics. She was unfailingly critical of the great Czech conductor Rafael Kubelík, described Janáček's orchestral work Taras Bulba as "trash" and even called Bartók's classic Music for Strings, Percussion and Celesta a "potboiler". Many people, have praised her as a great influence on the arts. Indeed, the Claudia Cassidy Theater in Chicago has been named in her honor.

Until 1965, her career mainly consisted of newspaper reviews for the Chicago Journal of Commerce, the Chicago Sun, and the Chicago Tribune, after which, while she continued to write for the Tribune, she also contributed to Chicago Magazine and made radio programs for WFMT.