Namesakes
Eurovision Song Contest Winners:
2 winners
Isabelle Aubret 1962 France 
France Gall (a.k.a. Isabelle) 1965 Luxembourg
Fictional Characters from Books:
1 character
Isabelle de Merteuil 1782 Dangerous Liaisons
Harry Potter Characters:
1 character
Fleur Delacour (middle name Isabelle)
Notable Actors and Entertainers:
2 actors, 1 model
Isabelle Huppert 1953-
Isabelle Adjani 1955-
Inès de La Fressange (middle name Isabelle) 1957-
Notable Athletes:
1 basketball
(basketball) Isabelle Yacoubou 1986-
Notable Musicians:
2 singers, 1 musician
Isabelle Aubret 1938-
France Gall (a.k.a. Isabelle) 1947-2018
Zaz (a.k.a. Isabelle) 1980-
Notable Writers:
1 author
Isabelle de Charrière 1740-1805
Olympic Medalists:
2 bronze, 1 gold, 1 silver
(bronze) Isabelle White 1912 diving - platform
(bronze) Isabelle Daniels 1956 4x100 m relay
(gold) Isabelle Chartrand 2002 ice hockey
(silver) Isabelle Yacoubou 2012 basketball
Other Royalty:
1 queen consort
Isabeau of Bavaria (a.k.a. Isabelle) 1385-1422 France
Saints:
1 blessed
Blessed Isabelle of France 1225-1270
Shakespearian Characters:
1 character
Isabel (a.k.a. Isabelle) Henry V