Rainier is a distinctive boys' name in United States, ranking #3328 in 2020 with 34 recorded births. The name reached its all-time peak in 2023 with 41 births ranking #3045. Since 1996, the popularity has increased by 277.8%. In 2020, approximately 1 in every 50,737 boys born was named Rainier. FALLING Recent data shows the name is currently falling.