Jansen may refer to:
People Jansen (surname), a Dutch-South African surname, cognate of Johnson
Places Jansen, Saskatchewan, Canada Jansen, Colorado, United States Jansen, Nebraska, United States
Other uses Jansen AG, Swiss steel and plastic company, founded by Josef Jansen of Aachen Jansen (crater), lunar crater named after Dutch inventor of the telescope Sacharias Jansen Jansen's metaphyseal chondrodysplasia, rare disease discovered by the orthopedic surgeon Murk Jansen Jansenism, Catholic theological movement named after the Dutch theologian Cornelius Jansen
See also Janse, Dutch surname Janson (disambiguation), Scandinavian surname Janssen (disambiguation), Dutch surname Janssens, Dutch surname Jannsen, a surname