Rainer is a distinctive boys' name in United States, ranking #7118 in 2003 with 10 recorded births. The name reached its all-time peak in 2018 with 53 births ranking #2464. Since 1996, the popularity has decreased by 33.3%. In 2003, approximately 1 in every 197,527 boys born was named Rainer. FALLING Recent data shows the name is currently falling.