Namesakes

Belgian Prime Ministers: 1 prime minister
Léon Delacroix (a.k.a. Gustave)   1918-1920  
French Presidents and Prime Ministers: 1 president
(president) René Coty (a.k.a. Gustave)   1954-1959  
Nobel Prize Winners: 1 literature, 1 physics
(literature) J. M. G. Le Clézio (a.k.a. Gustave)   2008  
(physics) Michel Mayor (a.k.a. Gustave)   2019  
Notable Artists: 1 architect, 1 engraver, 1 painter
Gustave Courbet   1819-1877  
Gustave Doré   1832-1883  
Alexandre Gustave Eiffel   1832-1923  
Notable Musicians: 1 composer
Gustave Charpentier   1860-1956     
Notable Scientists and Inventors: 1 astronomer
Michel Mayor (a.k.a. Gustave)   1942-  
Notable Writers: 1 author
Gustave Flaubert   1821-1880  
Olympic Medalists: 2 bronze
(bronze) Gustave Cabaret   1908   archery - continental style 50 m  
(bronze) Gustave Marinius Heiss   1932   fencing  
Other Royalty: 1 king
Baudouin of Belgium (a.k.a. Gustave)   1951-1993   Belgium  
Title Characters: 1 song
(song) Alexandre Gustave Eiffel   1991   Alec Eiffel