Kolby is a distinctive boys' name in United States, ranking #618 in 2008 with 401 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 64.3%. In 2008, approximately 1 in every 5,087 boys born was named Kolby. STABLE Recent data shows the name is currently stable.