Blau is an uncommon Jewish surname with origins in western Romania and Poland. Fur traders hunted arctic foxes for their blaufuchsfell, blue fox fur, and adopted the names Blaufuchs, Blaufuks, and Blaufück. These surnames were later shortened to Blau. Notable people with the surname include:
Alfred Blau (died 1896), French dramatist and opera librettist
Amram Blau, Israeli Neturei Karta rabbi
Daniel Blaufuks, a Portuguese photographer
Dick Blau (born 1943), Professor of Film at the University of Wisconsin-Milwaukee
Édouard Blau (1836–1906), French dramatist and opera librettist
Eric Blau (1921–2009), creator of the Off Broadway show Jacques Brel is Alive and Well and Living in Paris
Freda Meissner-Blau (born 1927), Austrian politician, activist, and founder and the federal spokesperson of the Austrian Green Party
Harry Blau (1885–1945), Latvian sports shooter
Herbert Blau (1926–2013), director and theoretician of performance
Hermann Blau (1871–1944), German engineer and chemist, and inventor of Blau gas
Joseph Leon Blau (1909–1986), American scholar of Jewish history and philosophy
Karl Blau, American musician
Lajos Bíró (born Blau), (1880–1948), Hungarian novelist, playwright, and screenwriter
Lajos Blau, Hungarian scholar and publicist
Leslie Blau, author, historian, and survivor of the Holocaust
Marietta Blau (1894–1970), Austrian physicist
Max Blau (1918–1984), Swiss chess
Peter Blau (1918–2002), Austrian Jewish sociologist
Rachel Blau DuPlessis (born 1941), American poet and essayist
Raphael Blau (1912–1996), American screenwriter
Rolf Blau (born 1952), retired German football midfielder
Theodore H. Blau (1928–2003), clinical, police and forensic psychologist who was the first clinician in independent practice to be elected president of the American Psychological Association in 1977
Tina Blau (1845–1916), Austrian painter
Uri Blau (born 1977), Israeli journalist and investigative reporter
Yaakov Blau (1929–2013), Israeli rabbi
Yosef Blau, president of the Religious Zionists of America and serves as the Mashgiach ruchani at Rabbi Isaac Elchanan Theological Seminary
