Leopold "Leo" von Singer (May 3, 1877 – March 5, 1951) was an American manager of an entertainment troupe called the Singer's Midgets, that were a popular vaudeville group in the first half of the twentieth century. He was responsible for casting many performers in the iconic film The Wizard of Oz
Singer was born to a prominent family in Vienna, Austria. He was reportedly inspired to form Singer's Midgets in 1912 or 1913, after he and his daughter Trudy were entertained by a troupe of little people at the Vienna Prater. With his wife, Walberga, Singer recruited little people for his own troupe, and began building the Liliputstadt, a "midget city" at the "Venice in Vienna" amusement park, where they could perform. Singer mainly sought out little people with proportionately-sized body parts – generally called "midgets", thus the name of the troupe – so that they could move and dance with ease.
The Liliputstadt was a major success, Singer began to tour with his performers throughout Europe and, in the process, recruited new members. After World War I broke out, the troupe traveled to the United States, and remained there for the remainder of their existence; they performed in vaudeville theaters. Because he was Austrian, the Bureau of Investigation (now the FBI) investigated Singer during World War I. In the end, the agents agreed with Singer’s claim that the accusations against him were based on “professional jealousy.” During the 1930s, some of Singer's Midgets began appearing in films, such as They Gave Him a Gun (1937), Block-Heads (1938), and The Terror of Tiny Town, a 1938 Western with an all-dwarf cast. Also in 1938, Singer signed a contract with Metro-Goldwyn-Mayer to provide 124 proportionately-sized little people to play Munchkins in The Wizard of Oz (1939). Some of the members of his troupe formed a portion of the group, and he traveled throughout the United States to recruit others.