Rainer is a distinctive boys' name in United States, ranking #3752 in 2006 with 27 recorded births. The name reached its all-time peak in 2018 with 53 births ranking #2464. Since 1996, the popularity has increased by 80.0%. In 2006, approximately 1 in every 76,116 boys born was named Rainer. FALLING Recent data shows the name is currently falling.