Hennessy is a distinctive girls' name in United States, ranking #2454 in 2009 with 78 recorded births. The name reached its all-time peak in 2019 with 82 births ranking #2239. Since 1996, the popularity has increased by 500.0%. In 2009, approximately 1 in every 23,550 girls born was named Hennessy. STABLE Recent data shows the name is currently stable.