Kellen is an Irish name usually traced to Caolán and the Gaelic word caol, so it means "slender" or "narrow"; some sources also connect it to a German surname. In the United States it took off in the 2000s, helped by NFL players such as Kellen Winslow. Kellen ranked number 671 in 2000, peaked at number 337 in 2012 and has fallen back to number 1069 in 2025.