Casimir is a distinctive boys' name in United States, ranking #2363 in 2023 with 58 recorded births. The name reached its all-time peak in 2025 with 73 births ranking #2039. Since 1996, the popularity has increased by 480.0%. In 2023, approximately 1 in every 29,458 boys born was named Casimir. RISING Recent data shows the name is currently rising.