Quick answer
Colby is a boy name.
Meaning and history
From an English surname, originally from various place names, derived from the Old Norse byname Koli (meaning "coal, dark") and býr "farm, settlement". As a given name, its popularity spiked in the United States and Canada in 2001 when Colby Donaldson (1974-) appeared on the reality television show Survivor.
Notes and context
Usage: english