Dalton is an English surname and place name from the Old English words for valley and settlement, so it means "valley town" or "settlement in the valley". Chemist John Dalton, who proposed modern atomic theory, is its most famous bearer, and in America the name has a Western, outlaw flavor thanks to the Dalton Gang. Dalton was a top 100 name in 2000 at number 91; it has dropped since and ranks number 448 in 2025.