Hennessy is a distinctive girls' name in United States, ranking #2986 in 2012 with 57 recorded births. The name reached its all-time peak in 2019 with 82 births ranking #2239. Since 1996, the popularity has increased by 338.5%. In 2012, approximately 1 in every 30,890 girls born was named Hennessy. STABLE Recent data shows the name is currently stable.