Allen is an English spelling of Alan, a Breton and Celtic name of uncertain origin that is usually explained as "little rock" or "handsome". Revolutionary hero Ethan Allen and basketball star Allen Iverson are among its American bearers, and it has long been a common surname as well. In the United States Allen ranked number 249 in 2000, peaked at number 243 in 2001 and has slipped to number 578 among boys' names in 2025.