Casimir is a distinctive boys' name in United States, ranking #2039 in 2025 with 73 recorded births. This places Casimir in the top 15% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2025 with 73 births ranking #2039. Since 1996, the popularity has increased by 630.0%. In 2025, approximately 1 in every 23,398 boys born was named Casimir. RISING Recent data shows the name is currently rising.