Hennessy is a distinctive girls' name in United States, ranking #5710 in 1997 with 17 recorded births. The name reached its all-time peak in 2019 with 82 births ranking #2239. Since 1996, the popularity has increased by 30.8%. In 1997, approximately 1 in every 102,392 girls born was named Hennessy. STABLE Recent data shows the name is currently stable.