Hennessy is a distinctive girls' name in United States, ranking #2711 in 2005 with 62 recorded births. The name reached its all-time peak in 2019 with 82 births ranking #2239. Since 1996, the popularity has increased by 376.9%. In 2005, approximately 1 in every 29,802 girls born was named Hennessy. STABLE Recent data shows the name is currently stable.