Colby is a distinctive girls' name in United States, ranking #2828 in 2025 with 60 recorded births. The name reached its all-time peak in 2000 with 155 births ranking #1262. Since 1996, the popularity has decreased by 41.2%. In 2025, approximately 1 in every 26,788 girls born was named Colby. RISING Recent data shows the name is currently rising.
Colby is an English surname-style name with a light, approachable sound. The older place-name meaning is less central to modern use than the name's friendly, sporty feel.
Like many names of its type, Colby entered first-name use through surname tradition and later settled into mainstream naming. It has a very late twentieth-century American profile.