Guillaume is a distinctive boys' name in United States, ranking #12881 in 2016 with 5 recorded births. The name reached its all-time peak in 1997 with 19 births ranking #3648. Since 1996, the popularity has decreased by 68.8%. In 2016, approximately 1 in every 379,442 boys born was named Guillaume. FALLING Recent data shows the name is currently falling.