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.
After the Protestant Reformation it was occasionally used as a given name in the English-speaking world, and it became somewhat common in America due to the fame of the revolutionary Ethan Allen (1738-1789). It only became popular towards the end of the 20th century. It is the name of the main character in Edith Wharton's novel Ethan Frome (1911), about a man in love with his wife's cousin.
A famous bearer of the surname was James Madison (1751-1836), one of the authors of the American constitution who later served as president (and after whom Madison Avenue was named).
This name was common among continental European royalty during the Middle Ages, and it was popularized in Britain by the German House of Hanover when they inherited the British throne in the 18th century. It was the name of characters in the novels Tom Jones (1749) by Henry Fielding and The Vicar of Wakefield (1766) by Oliver Goldsmith.
In the United States this name was only moderately common until the 1990s when it began rising in popularity, eventually becoming the most popular for girls from 2011 to 2013. A famous bearer is the Italian actress Sophia Loren (1934-).