Popularity trend for the name Sia in Aotearoa New Zealand, based on Department of Internal Affairs birth registrations.
Sia reached its highest rank of #256 for girls in 2022. In 2025, 16 babies were registered as Sia, ranking #263 for girls. Its popularity is rising compared with five years earlier. Sia is used mainly for girls.
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.