Kolby is a moderately popular boys' name in United States, ranking #359 in 2001 with 739 recorded births. This places Kolby in the top 3% of ranked US boys' names for the year. Its actual usage is classified as Moderately Popular. The name reached its all-time peak in 2001 with 739 births ranking #359. Since 1996, the popularity has increased by 202.9%. In 2001, approximately 1 in every 2,629 boys born was named Kolby. STABLE Recent data shows the name is currently stable.