Casimir is a distinctive boys' name in United States, ranking #3616 in 1997 with 19 recorded births. The name reached its all-time peak in 2025 with 73 births ranking #2039. Since 1996, the popularity has increased by 90.0%. In 1997, approximately 1 in every 99,215 boys born was named Casimir. RISING Recent data shows the name is currently rising.