Rein is a distinctive girls' name in United States, ranking #8751 in 2025 with 12 recorded births. This places Rein in the bottom 49% of ranked US girls' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2023 with 15 births ranking #7560. In 2025, approximately 1 in every 133,939 girls born was named Rein. RISING Recent data shows the name is currently rising.