List of Famous people born on April 21st

Arnaud Geyre was a racing cyclist from France who represented his native country at the 1956 Summer Olympics in Melbourne, Australia. There he won the gold medal in the men's team road race, alongside Michel Vermeulin and Maurice Moucheraud, and the silver in the men's individual road race. Geyre was a professional from 1958 to 1963.

Easley Blackwood is an American professor of music, a concert pianist, a composer of music, some using unusual tunings, and the author of books on music theory, including his research into the properties of microtonal tunings and traditional harmony.

Carl Stumpf was a German philosopher and psychologist. He studied with Franz Brentano at the University of Würzburg before receiving his doctorate at the University of Göttingen in 1868. He also tutored the modernist literature writer Robert Musil at the University of Berlin, and worked with Hermann Lotze, who is famous for his work in perception, at Göttingen. Stumpf is known for his work on the psychology of tones. He had an important influence on his students Wolfgang Köhler and Kurt Koffka who were instrumental in the founding of Gestalt psychology as well as Kurt Lewin, who was also a part of the Gestalt group and was key in the establishment of experimental social psychology in America. Stumpf is considered one of the pioneers of comparative musicology and ethnomusicology, as documented in his study of the origins of human musical cognition The Origins of Music (1911). He held positions in the philosophy departments at the Universities of Göttingen, Würzburg, Prague, Munich and Halle, before obtaining a professorship at the University of Berlin.

Nicole Julianne Sullivan is an American actress and comedienne. Sullivan is best known for her six seasons (1995–2001) on the sketch comedy series MADtv. She also played the role of Holly Shumpert for five seasons on the CBS sitcom The King of Queens.

Sergei Yakovlev, is a Kazakhstani professional road bicycle racer. He is currently without a team. He turned professional in 1999 and rode for Besson Chaussures for two seasons, then Acqua & Sapone and then he moved to Team Telekom which became T-Mobile. After fellow Kazakhstani Alexander Vinokourov left T-Mobile at the end of 2005, Yakovlev went with him to Liberty Seguros-Würth team and then the Astana cycling team. Yakovlev's victories include being the national champion of Kazakhstan in 2000, the 2000 edition of the Tour de l'Ain and a stage in the Tour de Suisse.