De Groot (pronounced [də ˈɣroːt]) is a surname of Dutch origin. It is sometimes Latinized as Grotius, as in the case of Hugo Grotius.
It is composed of the adjective groot, from middle Dutch grote, meaning big, tall or great, preceded by the definite article de, meaning the. It was originally a nickname for a tall person.
In 2007, there were 37,221 people in the Netherlands named De Groot, making it the 13th most common surname in the country.