The name is derived from a poetic English term for the song thrush, which is the name of a type of bird found in various breeds across Eurasia and Europe, especially England. The song thrush is known for its distinctive vocals and was kept as a house pet in 19th-century Europe. The word itself first entered the English language about 1400 and is ultimately from the Old French mauvis, which itself is possibly of Breton or Spanish origins. In modern French, this bird is now known as La Grive musicienne.

As a female given name, Mavis is first recorded in England in the late 16th-century, but became more widespread after Marie Corelli used it for the protoganist in her 1895 novel “The Sorrows of Satan.”

In the United States, the name peaked in popularity in 1927 coming in as the 270th most popular female name. The name fell off the U.S. Top 1000 in 1963. Oddly enough, the name has suddenly reappeared in the U.S. Top 1000 after over 50 years, coming in as the 789th most popular female name of 2016. It’s sudden resurgence seems to be a mystery, but is perhaps following along the coat-tails of other popular vintage names such as Lillian, Violet, and Emma.

Sources

https://www.behindthename.com/name/mavis
https://en.wikipedia.org/wiki/Song_thrush
https://www.etymonline.com/search?q=mavis
https://www.ssa.gov/cgi-bin/babyname.cgi