Leopold von Singer (May 3, 1877 – March 5, 1951) was an Austrian American who was the manager of the Singer Midgets, a popular vaudeville group in the first half of the twentieth century.

Jung Taek-woon (, born November 10, 1990), better known by his stage name Leo , is a South Korean singer, songwriter and actor, signed under Jellyfish Entertainment. Known for his high-pitched, sharp, and clear vocals, Leo debuted as a main vocalist of the South Korean boy group VIXX in May 2012, and began his acting career in 2014 in the musical Full House as Lee Young-jae. In 2015 he began his songwriting career, and with VIXX member Ravi formed VIXX's first official sub-unit VIXX LR.