Hennessy is a distinctive girls' name in United States, ranking #3058 in 2003 with 49 recorded births. The name reached its all-time peak in 2019 with 82 births ranking #2239. Since 1996, the popularity has increased by 276.9%. In 2003, approximately 1 in every 37,287 girls born was named Hennessy. STABLE Recent data shows the name is currently stable.