Collby \c(o)-ll-by\ as a boy's name is a variant of Colby (Old Norse), and the meaning of Collby is "swarthy person's settlement".

The baby name Collby sounds like Colbey, Gillby, Kellby and Kolby. Other similar baby names are Colley, Coby, Coley, Colle, Coll, Colla, Collis, Collie, Collin, Collen, Corby, Culley, Cully, Cobby and Wellby.