Cassius has been given to about 9,766 people in the United States since 1880. It was most common in 2021, which makes it a current name.
Cassius ranks 583rd among American boys in 2025, with 504 born that year. Its best year was 2021, when 612 babies were given the name, ranking 487th. The typical living American called Cassius is about 9 years old today. It is relatively most common in Hawaii, where it accounts for 0.12% of births.
Source: US Social Security Administration, national and state name files, 2025 release, and the Office for National Statistics for England and Wales. Etymology researched and written by our editors. Living-population and median-age figures are our own estimates, described in the methodology.