Popularity trend for the name Colby in Aotearoa New Zealand, based on Department of Internal Affairs birth registrations.
Colby reached its highest rank of #323 for boys in 2001. Colby did not appear in the 2025 figures, which only list names given to at least 10 babies. Its popularity is falling compared with five years earlier. Colby is used mainly for boys.
About this data: figures come from Department of Internal Affairs birth registrations for 1954-2025. The DIA only publishes a name for a given year when at least 10 babies were registered with it, so rarer names - and rarer spellings - are missing entirely, and a name can drop out of the record in quieter years. Spelling variants are counted separately, and counts reflect first names as registered.