Kolby is a distinctive girls' name in United States, ranking #6004 in 2007 with 23 recorded births. The name reached its all-time peak in 2000 with 55 births ranking #2690. Since 1996, the popularity has decreased by 42.5%. In 2007, approximately 1 in every 83,585 girls born was named Kolby. STABLE Recent data shows the name is currently stable.