Cullen is a distinctive boys' name in United States, ranking #619 in 2002 with 318 recorded births. The name reached its all-time peak in 2010 with 679 births ranking #413. Since 1996, the popularity has decreased by 18.9%. In 2002, approximately 1 in every 6,105 boys born was named Cullen. FALLING Recent data shows the name is currently falling.