Willem is a distinctive boys' name in United States, ranking #1208 in 2003 with 122 recorded births. The name reached its all-time peak in 2003 with 122 births ranking #1208. Since 1996, the popularity has increased by 165.2%. In 2003, approximately 1 in every 16,191 boys born was named Willem. STABLE Recent data shows the name is currently stable.