Ditlevsen is a surname. It is the surname of:

• Knud Ditlevsen (1925–2006), Danish sprint canoer
• Richard G. Ditlevsen Jr. (born 1957), American businessman and stunt performer
• Sara Hjort Ditlevsen, Danish actor, 2012 winner of Bodil Award for Best Actress in a Leading Role
• Susanne Ditlevsen, Danish mathematician and statistician
• Tove Ditlevsen (1917–1976), Danish poet and author

• Constantine Hangerli
• Constantine Harmenopoulos
• Constantine, Hereditary Prince of Löwenstein-Wertheim-Rosenberg
• Constantine Hering
• Constantine I And Christianity
• Constantine I (emperor)
• Constantine III of Armenia
• Constantine III of Gallura
• Constantine III (Scotland)
• Constantine III (usurper)
• Constantine II of Alba
• Constantine II of Armenia
• Constantine II of Britain
• Constantine II of Bulgaria
• Constantine II of Byzantine
• Constantine II of Cagliari
• Constantine II of Constantinople
• Constantine II of Georgia
• Constantine II of Kakheti
• Constantine II of Logudoro
• Constantine II of Torres
• Constantine II (Scotland)
• Constantine I, King of Scots
• Constantine I of Arborea
• Constantine I of Armenia