Pronounced lee-sha, Laoise is the feminine form of the Irish mythological names Lugh and Lugus, which means light. Lugus was the Celtic god of commerce and craftsmanship, the equivalent of the Roman Mercury, thought to inspire the later Irish hero Lugh. Laoise is among the Top 100 Irish names for girls, but Americans will definitely have pronunciation issues.

Authentically spelled Luíseach (with Luighsech as a variant), this obscure saint's name is thought to derive from the mythological figure Lugh, perhaps a reflex of an older god. Luíseach is sometimes considered the Irish version of Lucy. In fact, they are historically separate names, but if Lugh derives from a Proto-Indo-European root meaning "shining" then they are very distant cousins.