Koa is a Hawaiian name that means "warrior" or "brave" and is also the name of Hawaii's prized acacia tree, whose wood was used for canoes and surfboards. Short and open-voweled, it has crossed from the islands to the mainland alongside Kai and Kainoa. Koa entered the US top 1000 in 2017 and has climbed quickly, from number 1158 in 2015 to number 269 among boys' names in 2025, its highest rank so far.