Cassius is a moderately popular boys' name in United States, ranking #485 in 2021 with 607 recorded births. The name reached its all-time peak in 2021 with 607 births ranking #485. Since 1996, the popularity has increased by 1,345.2%. In 2021, approximately 1 in every 2,880 boys born was named Cassius. STABLE Recent data shows the name is currently stable.