Hennessy is a distinctive girls' name in United States, ranking #3482 in 2002 with 39 recorded births. The name reached its all-time peak in 2019 with 82 births ranking #2239. Since 1996, the popularity has increased by 200.0%. In 2002, approximately 1 in every 46,072 girls born was named Hennessy. STABLE Recent data shows the name is currently stable.