Declan is a moderately popular boys' name in United States, ranking #114 in 2022 with 3,344 recorded births. The name reached its all-time peak in 2019 with 3,971 births ranking #95. Since 1996, the popularity has increased by 3,084.8%. In 2022, approximately 1 in every 522 boys born was named Declan. FALLING Recent data shows the name is currently falling.