Rainier is a distinctive boys' name in United States, ranking #3288 in 2015 with 35 recorded births. The name reached its all-time peak in 2023 with 41 births ranking #3045. Since 1996, the popularity has increased by 288.9%. In 2015, approximately 1 in every 54,750 boys born was named Rainier. FALLING Recent data shows the name is currently falling.