Claire Beck Loos (November 4, 1904 - January 15, 1942*) was a Czechoslovakian photographer and writer. She was the third wife of early modernist Czechoslovak-Austrian architect Adolf Loos. She worked in the atelier of Hede Pollak in Prague and studied photography in Vienna at the Graphische Lehr- und Versuchsanstalt. In 1936, she published Adolf Loos Privat, a literary work of anecdotes about her ex-husband's character, habits, and sayings. Published by the Johannes-Presse in Vienna, the book was intended to raise funds for Adolf Loos's tomb, as he had died destitute three years earlier. She moved to Prague at the beginning of World War II. She was deported to Theresienstadt at the end of 1941 and from there to Riga, Latvia, where she was killed in the Holocaust. *Her death date is thus only an estimate.