This name was borne by the heroine of Lewis Carroll's novels Alice's Adventures in Wonderland (1865) and Through the Looking Glass (1871).
Due to the popularity of the saint, the name became common in the Christian world during the Middle Ages. The Normans brought it to England, where it was commonly spelled Cecily — the Latinate form Cecilia came into use in the 18th century.
This name was fairly common in France, England and the United States in the early 20th century. It became quite popular in France and England at the end of the 20th century, just when it was at a low point in the United States. It quickly climbed the American charts and entered the top ten in 2014.
Already growing in popularity due to Australian model Elle Macpherson (1964-), this name received a boost in the United States after the release of the 2001 movie Legally Blonde featuring the main character Elle Woods. In the United Kingdom the name was already fairly common at the time the movie came out, and it actually started declining there shortly afterwards. A famous bearer is American actress Elle Fanning (1998-).
There was a medieval English form of this name, Helewis, though it died out after the 13th century. In the 19th century it was revived in the English-speaking world in the form Eloise.
This name can also be given in reference to the city in Italy, as in the case of Florence Nightingale (1820-1910), who was born there to British parents. She was a nurse in military hospitals during the Crimean War and is usually considered the founder of modern nursing.