Namesakes
French Presidents and Prime Ministers:
1 prime minister
(prime minister) Armand-Emmanuel de Vignerot du Plessis, Duc de Richelieu 1815-1818; 1820-1821 
Notable Athletes:
4 rugby, 1 cricket
(rugby) Jannie du Plessis 1982-
(rugby) Tinus du Plessis 1984-
(rugby) Bismarck du Plessis 1984-
(cricket) Faf du Plessis 1984-
(rugby) JP du Plessis 1991-
Notable Musicians:
1 singer
Jay (a.k.a. du Plessis) 1977- pop