Cosmo is a distinctive boys' name in England & Wales, ranking #751 in 2021 with 45 recorded births. This places Cosmo in the top 12% of ranked UK boys' names for the year. Its actual usage is classified as Uncommon. The name reached its all-time peak in 2025 with 57 births ranking #639. Since 1996, the popularity has increased by 800.0%. In 2021, approximately 1 in every 6,555 boys born was named Cosmo. STABLE Recent data shows the name is currently stable.