Cosmo is a distinctive boys' name in United States, ranking #1934 in 2025 with 80 recorded births. This places Cosmo in the top 14% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2022 with 99 births ranking #1708. Since 1996, the popularity has increased by 300.0%. In 2025, approximately 1 in every 21,351 boys born was named Cosmo. FALLING Recent data shows the name is currently falling.