Kacia is of Hebrew origin, meaning "pure". It's a variant spelling of the name Kasia, which is itself a Polish form of Katherine. The name gained popularity during the late 20th century, often chosen for its unique sound and modern feel while still having traditional roots. Kacia is sometimes associated with the gemstone kyanite, known for its strength and resilience.
"The name Kacia experienced periods of popularity and decline over the years, with notable spikes in the late 80s to early 90s, peaking at 17 births in 1990. However, it has since become much less common, with five or fewer births per year from 2005 onwards."