Kolby is a distinctive boys' name in United States, ranking #1146 in 2017 with 166 recorded births. This places Kolby in the top 8% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2001 with 739 births ranking #359. Since 1996, the popularity has decreased by 32.0%. In 2017, approximately 1 in every 11,146 boys born was named Kolby. STABLE Recent data shows the name is currently stable.