Kolby is a distinctive boys' name in United States, ranking #521 in 1999 with 407 recorded births. This places Kolby in the top 4% of ranked US boys' names for the year. Its actual usage is classified as Uncommon. The name reached its all-time peak in 2001 with 739 births ranking #359. Since 1996, the popularity has increased by 66.8%. In 1999, approximately 1 in every 4,718 boys born was named Kolby. STABLE Recent data shows the name is currently stable.