Kolby is a moderately popular boys' name in United States, ranking #464 in 2003 with 543 recorded births. The name reached its all-time peak in 2001 with 739 births ranking #359. Since 1996, the popularity has increased by 122.5%. In 2003, approximately 1 in every 3,638 boys born was named Kolby. STABLE Recent data shows the name is currently stable.