Hennessy is a distinctive girls' name in United States, ranking #3544 in 2016 with 44 recorded births. The name reached its all-time peak in 2019 with 82 births ranking #2239. Since 1996, the popularity has increased by 238.5%. In 2016, approximately 1 in every 40,261 girls born was named Hennessy. STABLE Recent data shows the name is currently stable.