Claessen

Claessen is a Dutch patronymic surname ("son of Claes"). Notable people with the surname include:


 * Bart Claessen (born 1980), Dutch dance DJ known as Barthezz
 * George Claessen (1909–1999), Sri Lankan artist and poet
 * Gustave Claessen (fl. 1920), Belgian cyclist
 * Hans Claessen (1562–1623), Dutch merchant and founder of the New Netherland Company
 * Henri J. M. Claessen (1930–2022), Dutch anthropologist
 * Roger Claessen (1941–1982), Belgian football player
 * Claesen
 * (born 1956), Belgian conductor
 * Nico Claesen (born 1962), Belgian football player