Hennessy is a distinctive girls' name in United States, ranking #2780 in 2013 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 2013, approximately 1 in every 28,297 girls born was named Hennessy. STABLE Recent data shows the name is currently stable.