Rainier is a distinctive boys' name in United States, ranking #4800 in 2010 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 2010, approximately 1 in every 95,921 boys born was named Rainier. FALLING Recent data shows the name is currently falling.