Margaretha "Mandy" de Jongh (born 27 December 1961)[1] is a taekwondo practitioner from the Netherlands.

In 1987 she won the World Championships in the middleweight (then −70 kg) category.

Next year, she received an unofficial silver medal in the same weight category at the 1988 Summer Olympics (taekwondo was then an exhibition event).

[4] Next to taekwondo she was a switchboard operator and receptionist at the Ministry of Education.

This biographical article related to taekwondo in the Netherlands is a stub.