Boonzaier (variously spelled Boonzayer, Boonzaayer, and Boonzaaijer) is a Dutch and Afrikaans surname literally translated as "bean sower", but actually referring to "bone setters", or a form of early chiropracty. Notable individuals with this last name include:
D. C. Boonzaier (1865–1950), South African cartoonist Floretta Boonzaier (born 1974), South African psychologist Gregoire Boonzaier (1909–2005), South African artist and son of D. C. Boonzaier Janneke Boonzaaijer (born 1996), Dutch equestrian John Boonzaaijer (born 1968), American Anglican bishop Martin Boonzaayer (born 1972), American judoka