Could Cassius be the perfect name for your baby boy? The baby boy name Cassius is 7 letters long, and contains 3 vowel(s) and 4 consonant(s). Cassius is a baby boy name that starts with the letter C and ends in the letter S. The baby boy name Cassius has a popularity of 51% and is ranked 488 in the list of top 1000 most popular baby boy names. If Cassius isn't the ideal name for your baby boy then take a look here for some randomly generated names. Hopefully you'll find a more suitable first name for your baby boy than Cassius!