Trey is an American name taken from the word trey, meaning "three" in cards and dice, which goes back to the Old French treis. It began as a nickname for a boy who was "the third" to carry his father's and grandfather's name and then became a given name on its own. Trey ranked number 215 in 2000 and peaked at number 213 in 2002, but has fallen steadily since, to number 890 in 2025.