Llewellyn is a distinctive boys' name in United States, ranking #6539 in 2021 with 13 recorded births. The name reached its all-time peak in 2025 with 16 births ranking #5749. Since 1996, the popularity has increased by 85.7%. In 2021, approximately 1 in every 134,480 boys born was named Llewellyn. RISING Recent data shows the name is currently rising.