Coby is a distinctive girls' name in England & Wales, ranking #5201 in 2007 with 3 recorded births. The name reached its all-time peak in 1996 with 5 births ranking #2683. Since 1996, the popularity has decreased by 40.0%. In 2007, approximately 1 in every 102,038 girls born was named Coby. STABLE Recent data shows the name is currently stable.
Coby is a compact English short form of Jacob. That gives it a much clearer source line than the earlier broad discussion of several overlapping variant families.
As a nickname-style form, Coby works because it sounds casual and familiar while still resting on a major biblical classic. Its modern use is more flexible, but the Jacob connection is the clearest core route.