Hennessy is a distinctive boys' name in United States, ranking #11397 in 2024 with 6 recorded births. The name reached its all-time peak in 1996 with 7 births ranking #7432. Since 1996, the popularity has decreased by 14.3%. In 2024, approximately 1 in every 285,886 boys born was named Hennessy. STABLE Recent data shows the name is currently stable.