It was rare as an American given name before 1975. In the mid-1980s it began growing in popularity for boys after a character by this name began appearing on the soap opera Ryan's Hope. It is now more common as a feminine name, probably due to the fame of the actress Dakota Fanning (1994-).
As an English name, Chloe has been in use since the Protestant Reformation. It started getting more popular in the 1980s in the United Kingdom and then the United States. It was the most popular name for girls in England and Wales from 1997 to 2002. This is one of the few English-language names that is often written with a diaeresis, as Chloë.