Mercedes comes from the Spanish Catholic title María de las Mercedes ("Our Lady of Mercies"). The Latin root merces means "reward" or "mercy."
Mercedes peaked at #134 in the U.S. in 1996. The Mercedes-Benz car brand was named after Mercedes Jellinek, daughter of the company's founder.
Mercedes 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 Mercedes reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.