Claassens is an Afrikaans, Dutch and Low German patronymic surname. Notable people with the surname include:
Jannie Claassens (born 1969), South African rugby union player Johnny Claassens, South African footballer Errie Claassens (born 1981), South African rugby union player Michael Claassens (born 1982), South African rugby union player
See also
Claassen Claessen Claessens Clason Classen Classun Clausen Claussen Klaassen Klassen