Gustaaf
Gustaaf may refer to:
- Gustaaf Van Cauter,, former racing cyclist
- Gustaaf Deloor, Belgian road racing cyclist
- Gustaaf Eeckeman, Belgian football left winger
- Gustaaf Adolf van den Bergh van Eysinga, Dutch theologian
- Boudewijn Albert Karel Leopold Axel Maria Gustaaf, King of the Belgians from 1951 until his death
- Gustaaf Hermans, former Belgian cyclist
- Gustaaf Bernard Jozef Hiltermann, Dutch journalist, jurist, political commentator, publisher, historian
- Gustaaf Hulstaert, Belgian missionary in the Belgian Congo from 1925
- Gustaaf van Hulstijn, Dutch fencer
- Gustaaf Willem van Imhoff, Dutch colonial administrator for the Dutch East India Company
- Gustaaf Joos, prelate of the Diocese of Ghent
- Julius Gustaaf Arnout Koenders, Surinamese teacher and fervent activist for Sranan Tongo
- Gustaaf Lauwereins, Belgian judoka
- Adolf Gustaaf Lembong, Indonesian military officer involved in guerrilla warfare against Japan in the Philippines during World War II
- Gustaaf Adolf Maengkom, former Indonesian Minister of Justice in the Djuanda Cabinet and Indonesian ambassador to Poland
- Gustaaf [Adolf Frederik Molengraaff], Dutch geologist, biologist and explorer
- Gustaaf Martinus Oosterling, early Surinamese photographer
- Gustaaf Pelsmaecker or Auguste Pelsmaeker, Belgian footballer
- Gustaaf Van Roosbroeck, Belgian professional road bicycle racer
- Gustaaf Sap or Gustave Sap, Belgian politician and minister for the Catholic Party
- Gustaaf Schlegel, Dutch sinologist and field naturalist
- Gustaaf Segers, Flemish writer, Dutch and German teacher and Vondel scholar
- Gustaaf Van Slembrouck, Belgian professional cyclist from 1926 to 1934, nicknamed 'Den Staf'
- Gustaaf De Smet, Belgian cyclist
- Gustaaf Sorel, Belgian painter and draughtsman
- Gustaaf Uhlenbeek, Dutch former footballer
- Gustaaf Wappers, Belgian painter