Rainer is a distinctive boys' name in United States, ranking #6710 in 2000 with 10 recorded births. This places Rainer in the bottom 45% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2018 with 53 births ranking #2464. Since 1996, the popularity has decreased by 33.3%. In 2000, approximately 1 in every 196,393 boys born was named Rainer. FALLING Recent data shows the name is currently falling.