Guillaume is a distinctive boys' name in United States, ranking #10026 in 2013 with 7 recorded births. The name reached its all-time peak in 1997 with 19 births ranking #3648. Since 1996, the popularity has decreased by 56.3%. In 2013, approximately 1 in every 270,179 boys born was named Guillaume. FALLING Recent data shows the name is currently falling.