Kolby is a distinctive girls' name in United States, ranking #2689 in 1999 with 52 recorded births. The name reached its all-time peak in 2000 with 55 births ranking #2690. Since 1996, the popularity has increased by 30.0%. In 1999, approximately 1 in every 34,111 girls born was named Kolby. STABLE Recent data shows the name is currently stable.