Rei is a distinctive boys' name in United States, ranking #3695 in 2019 with 30 recorded births. This places Rei in the top 26% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2025 with 35 births ranking #3363. In 2019, approximately 1 in every 59,779 boys born was named Rei. RISING Recent data shows the name is currently rising.