Fionn is a distinctive boys' name in England & Wales, ranking #658 in 2025 with 55 recorded births. The name reached its all-time peak in 2022 with 69 births ranking #555. Since 1996, the popularity has increased by 323.1%. In 2025, approximately 1 in every 4,944 boys born was named Fionn. STABLE Recent data shows the name is currently stable.