Noah was the most popular boys' name in Co Roscommon last year.
It was Páidi in Longford, and Jack and Rían were the top picks in Leitrim.
The most popular girls' name in Longford last year was Sadie - with Amelia, Katie and Saoirse the most popular for Leitrim mothers.
The CSO found Kate and Éabha were the top girls' choices in Roscommon.