Mailei is of Hawaiian origin, meaning "third-born child" in the Hawaiian language. It is a unisex name, traditionally given to both boys and girls who are the third child in their family. The name Mailei is also associated with the Hawaiian custom of naming children after their birth order, which follows a specific pattern: Kaikaina (firstborn), Mailei (third-born), and Kimo or Keikiwiki (youngest). This naming tradition reflects the importance of family and community in Hawaiian culture. In recent years, Mailei has gained popularity beyond Hawaii, becoming an appealing choice for parents seeking unique and meaningful names for their children.
Mailei had 20 babies named over a span of twelve years.