Reilly is a distinctive girls' name in United States, ranking #876 in 2003 with 276 recorded births. The name reached its all-time peak in 1998 with 379 births ranking #623. Since 1996, the popularity has increased by 59.5%. In 2003, approximately 1 in every 6,620 girls born was named Reilly. RISING Recent data shows the name is currently rising.