The name Eilish is a girl's name of Irish origin meaning "pledged to God".

Eilish is one of those Irish names that, thanks to a celebrity, has suddenly become much more familiar to English speakers. Irish-American singer Billie Eilish (Eilish is actually one of her middle names) introduced the wider world to this Irish name as actress Saoirse Ronan did with hers. Interestingly, Saoirse Ronan's character in Brooklyn, based on the novel by Colm Toibin, was named Eilis, pronounced AY-lish. While the Anglicized version of Eilish or Eilis is usually given as Elizabeth, it is sometimes translated to Alice, which is closer to the AY-lish pronunciation.