Libby is a name of English origin and it's often considered to be a diminutive form of the name Elizabeth. However, its true origins are somewhat unclear as there are no records of it being used independently before the early 20th century.
The name Elizabeth has a long history and means "God is my oath" in Hebrew. It was borne by several queens of England, including Elizabeth I, who ruled from 1558 to 1603. This might have contributed to the popularity of its diminutives such as Libby.
In literature, the name Libby has been used in various works, most notably in the novel "To Kill a Mockingbird" by Harper Lee, where one of the main characters is named Scout Finch, whose full name is Jean Louise Finch but who is often called by her nickname Libby. This might have helped to popularize the name further.
Today, Libby remains a popular name for girls in English-speaking countries. It's often associated with warmth and approachability due to its casual, friendly sound. Despite its unclear origins, the name Libby has managed to carve out a place for itself in the pantheon of popular girls' names.
"Libby peaked in popularity around the turn of the century, with over 200 births annually from 1956 onwards. However, it has since declined significantly, with fewer than 250 births recorded each year since 2011."