In Britain the parallel form Alice, derived via Old French, has historically been more common than Adelaide, though this form did gain some currency in the 19th century due to the popularity of the German-born wife of King William IV, for whom the city of Adelaide in Australia was named in 1836.
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.
This name got more popular in the early 1980s, then got a boost in 1990 when it was used by the main character in the movie Days of Thunder.
Originally more common as a name for boys in America, it became more popular for girls in the 1960s. It began rapidly increasing after 1973, possibly due to a character (played by Natalie Wood) in the television movie The Affair. It reached an apex in the United States ranked 17th in 1990, though it has quickly fallen away since then.
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-).
This name was popular throughout the English-speaking world in the early 20th century. It staged a comeback in the early 21st century, returning to the American top ten in 2017.