A famous bearer was the American jazz musician Nina Simone (1933-2003).
As an English name it has been very popular since the Middle Ages. It was the top name for girls in England and Wales in the 1920s, 30s and 40s, but it declined in the latter half of the 20th century.
Other saints by this name include a queen of Scotland and a princess of Hungary. It was also borne by Queen Margaret I of Denmark, who united Denmark, Sweden, and Norway in the 14th century. Famous literary bearers include American writer Margaret Mitchell (1900-1949), the author of Gone with the Wind, and Canadian writer Margaret Atwood (1939-). Others include American anthropologist Margaret Mead (1901-1978) and British prime minister Margaret Thatcher (1925-2013).
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.
As an English name it can also derive from the month of August, which was named for the Roman emperor Augustus.