Surname קולבי (Colby 
, Colbie 
, קולבי 
) , worldwide, is a common last name. The cognomen קולבי is habitual in the United States, where it is quite a rare surname, Canada, and New Zealand. Measured by absolute frequency, the name is most common in the United States, the United Kingdom, and Canada. Likewise, קולבי is the forename as well as the last name.