Cullen is a distinctive boys' name in United States, ranking #792 in 2006 with 260 recorded births. The name reached its all-time peak in 2010 with 679 births ranking #413. Since 1996, the popularity has decreased by 33.7%. In 2006, approximately 1 in every 7,904 boys born was named Cullen. FALLING Recent data shows the name is currently falling.