Leonor is the Spanish-Portuguese form of Eleanor — from Greek helios (sun, light). Leonor de Borbón (born 2005) is the Princess of Asturias, the current heir apparent to the Spanish throne — daughter of King Felipe VI. Eight Iberian queens have borne the name.
Leonor of Castile (1241-1290) was the Spanish princess who married Edward I of England — when she died, he marked her funeral journey with twelve Eleanor Crosses across England.
Leonor 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 Leonor reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.