Isabelle is the French form of Elizabeth — from the Hebrew Elisheba ("my God is my oath"). A top-100 US baby name since 2007. Has worked with Michael Haneke (The Piano Teacher 2001), Claire Denis, Paul Verhoeven, Hong Sang-soo, and Catherine Breillat — a uniquely sustained collaboration with the auteur-art-film canon spanning 50+ years and 150+ films. Isabelle Allende — covered separately as Isabel. Isabelle Daza — Filipino actress.
Isabelle does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Isabelle reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.