Rainier is a distinctive boys' name in United States, ranking #4820 in 2014 with 20 recorded births. The name reached its all-time peak in 2023 with 41 births ranking #3045. Since 1996, the popularity has increased by 122.2%. In 2014, approximately 1 in every 96,022 boys born was named Rainier. FALLING Recent data shows the name is currently falling.