Ellis is the Anglicized form of the Welsh Elis — from the Hebrew Eliyāhū (Elijah, "my God is Yahweh"). Ellis Marsalis Jr. Ellis Davidson — American actress. Ellis Genge — male; English rugby player.
Ellis 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 Ellis reduce to 3, The Communicator. This is a traditional interpretive system, not a factual claim about the name.