Gillermo is a distinctive boys' name in United States, ranking #4319 in 1997 with 15 recorded births. The name reached its all-time peak in 1998 with 21 births ranking #3534. Since 1996, the popularity has increased by 15.4%. In 1997, approximately 1 in every 125,673 boys born was named Gillermo. FALLING Recent data shows the name is currently falling.