Hennessey is a distinctive girls' name in United States, ranking #10687 in 2022 with 9 recorded births. The name reached its all-time peak in 2015 with 27 births ranking #5037. Since 1996, the popularity has increased by 50.0%. In 2022, approximately 1 in every 182,085 girls born was named Hennessey. FALLING Recent data shows the name is currently falling.