Hennessy is a distinctive girls' name in United States, ranking #2599 in 2021 with 67 recorded births. The name reached its all-time peak in 2019 with 82 births ranking #2239. Since 1996, the popularity has increased by 415.4%. In 2021, approximately 1 in every 24,473 girls born was named Hennessy. STABLE Recent data shows the name is currently stable.