Due to the saint's popularity, the name came into general use in medieval Europe, especially in Spain and France. It was also borne by a 16th-century king of Portugal who died in a crusade against Morocco.
Very rare as an American given name before 1980, it increased in popularity in the 1980s and 90s. It got a boost in 2004 after the debut of the television series Lost, which featured a character by this name.
As a given name, it took off in popularity during the 1990s. It has been more common for girls in the United States probably because of its similarity to other names such as Megan, Morgan and Regan.
In England and elsewhere in Europe during the Middle Ages this name was used in honour of the saint. However, it was not generally given in Ireland before the 17th century because it was considered too sacred for everyday use. It has since become very common there.
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).
The name has been very common throughout the English-speaking world since end of the 20th century. In the United States it reached a high point in 2017, when it ranked as the fifth most popular name for boys.
This is the most common spelling of this name in the United Kingdom, Australia and New Zealand; in the United States the spellings Haley and Hailey are more popular.
The most notable bearer of the name was Cyrus the Great, the founder of the Achaemenid Persian Empire in the 6th century BC. He is famous in the Old Testament for freeing the captive Jews and allowing them to return to Israel after his conquest of Babylon. As an English name, it first came into use among the Puritans after the Protestant Reformation.
In the English-speaking world this name is more commonly given to girls. This is due to the American actress Alexis Smith (1921-1993), who began appearing in movies in the early 1940s. It got a boost in popularity in the 1980s from a character on the soap opera Dynasty.