Estelle is the French form of Latin Stella — both meaning "star." The same root gives Esther, Stella, Estrella, and the constellations.
Estelle was popular in the late 19th century, peaking at #66 in 1880. After decades of decline, it has returned in the 2020s as part of the vintage revival. Today it sits in the U.S. top 600 and is climbing fast.
Estelle 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 Estelle reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.