Head to head · Boys' names
Cassius vs Seth
#582 vs #581 in 2025 · both stepping back from its peak
Seth is a whisker ahead (#581 vs #582 in 2025) and both are stepping back from its peak. The records will not split these two — sound, story and your own last name will.
Cast your vote
Which one would you pick?
Your gut first, the numbers after — the split shows once you pick.
The tale of the tape
On the charts, Seth leads 4 measures of 6; Cassius leads 0.
Ranks, counts and years are measured in the official US birth record; the classroom and living figures are estimates computed from it. The dot marks the side each measure favours on the charts — more common, not better.
What the records say
146 years of US births, drawn on one scale
Two curves, one scale
Who owned which decade
- 1880s: Cassius #691, Seth #333 — Seth higher
- 1890s: Cassius #839, Seth #500 — Seth higher
- 1900s: Cassius #1373, Seth #559 — Seth higher
- 1910s: Cassius #2071, Seth #649 — Seth higher
- 1920s: Cassius #2616, Seth #695 — Seth higher
- 1930s: Cassius #3012, Seth #797 — Seth higher
- 1940s: Cassius #2714, Seth #710 — Seth higher
- 1950s: Cassius #3273, Seth #527 — Seth higher
- 1960s: Cassius #1668, Seth #408 — Seth higher
- 1970s: Cassius #2415, Seth #174 — Seth higher
- 1980s: Cassius #2548, Seth #97 — Seth higher
- 1990s: Cassius #2038, Seth #93 — Seth higher
- 2000s: Cassius #1375, Seth #94 — Seth higher
- 2010s: Cassius #721, Seth #269 — Seth higher
- 2020s: Cassius #542, Seth #509 — Seth higher
Seth stood higher in every recorded decade — 15 of 15.
Rank by decade
| Decade | Cassius | Seth |
|---|---|---|
| 1880s | #691 | #333 |
| 1890s | #839 | #500 |
| 1900s | #1373 | #559 |
| 1910s | #2071 | #649 |
| 1920s | #2616 | #695 |
| 1930s | #3012 | #797 |
| 1940s | #2714 | #710 |
| 1950s | #3273 | #527 |
| 1960s | #1668 | #408 |
| 1970s | #2415 | #174 |
| 1980s | #2548 | #97 |
| 1990s | #2038 | #93 |
| 2000s | #1375 | #94 |
| 2010s | #721 | #269 |
| 2020s | #542 | #509 |
Average national rank across each decade. A dash means the name sat outside the recorded top of that decade.
The names themselves
Meaning, roots, sound and the people who carried each
Where each name comes from
Cassius
Most often read as "empty, hollow, vain," from Latin cassus
Two positions compete. The standard proposal links the family name to the Latin adjective cassus, "empty" or "hollow" — the same root behind words for something void. The other holds that Cassius, like many old Roman clan names, is simply older than Latin etymology can reach, an Italic family label whose sense was already lost by the Republic. Roman nomina were inherited, not chosen for meaning, so the family carried it for centuries without anyone taking it as a description.
Cassius (Roman nomen) → Cassianus → Cassian → Cassio
How it traveled
Cassius began as a Roman nomen, the name of the gens Cassia, a family present in Rome's records from the early Republic onward. Its best-known bearer, Gaius Cassius Longinus, joined the conspiracy against Julius Caesar in 44 BC — which is how the name reached English readers, first through Roman historians and then through Shakespeare, who gave Cassius some of the most quoted lines in Julius Caesar.
Seth
appointed, placed
The reading comes from the Hebrew verb shith, 'to set or place', and Genesis 4:25 makes the connection explicit: Eve names her son because God has appointed her another child in place of Abel.
Shet (Hebrew) → Sēth (Greek) → Seth (Latin) → Seth (English)
How it traveled
The name is Hebrew — Shet — and belongs to the third son of Adam and Eve in Genesis, the one through whom the genealogies continue. The Greek translators of the Hebrew Bible rendered it Sēth, Latin kept that spelling, and English inherited it unchanged, which is why the modern form looks so close to the original.
Where a reading is contested the note says so — this page does not turn a guess into a fact. The chain is each name's recorded forms, oldest first; the story is its opening, told in full on the name's own page.
Out loud, and in short
Cassius
KASH-us
Two pronunciations circulate in American English: KASH-us, the more common, and the three-syllable KASS-ee-us, closer to the Latin KAS-see-oos. Both are correct; families generally pick one and repeat it.
- Cass — The default short form, used for boys and girls alike; also given on its own as a full name.
- Cash — An informal shortening that has grown alongside Cash as an independent given name for boys.
- Cas — A spelling variant of the same short form, more common in writing than in speech.
- Cassie — Heard occasionally, though in the US it attaches far more often to Cassandra and Cassidy, and reads as feminine to most ears.
Seth
SETH
One syllable, rhyming with 'breath'. There is only one pronunciation in English, and the spelling gives it away completely.
- Sethy — Almost entirely a family diminutive used with small children; rarely survives into school years.
- Sethie — A spelling variant of the same affectionate childhood form; informal only.
Is it right for you
The differences that decide it, laid out by what you want
Choose by what you want
Choose Cassius if you want…
- a name with more sound in itCassius runs 3 syllables, Seth 1
- plenty of nickname options4 recorded short forms — Cass, Cash and Cas
- a name that ages quietlyan estimated 40% chance of feeling dated by 2040, against 72% for Seth
Choose Seth if you want…
- a name past its most crowded yearsSeth is stepping back from its peak
- a name with fewer syllablesSeth is 1 syllable to Cassius's 3
- a name that feels very nowSeth is stepping back from its peak
Each line is a measured difference between the two names — a rank, a count, a recorded form — never a judgement of either. Save the one that answers your question; it lands on your shortlist.
The trade-offs, name by name
Cassius
Strengths
- An unbroken written record from the Roman Republic to the present, so the spelling is already familiar to anyone who has read Shakespeare or Roman history.
- Two established one-syllable short forms, Cass and Cash, both in genuine use.
- Recognizable across Italian, Portuguese, Spanish and Polish in forms close enough that the name survives a border.
To consider
- The pronunciation genuinely splits: KASH-us and KASS-ee-us are both in use, so he will correct people, or be corrected, throughout his life. Choosing one early and using it consistently is most of the fix.
- The leading etymology, Latin cassus, means "empty" or "hollow" — an unappealing reading if a meaning matters to you, though Roman families inherited such names without ever treating them as descriptions.
- The strongest historical association is with the conspirator who helped kill Caesar, and Shakespeare's portrait of him is not flattering. Most people recall the name before the plot, but some readers will make the link.
Seth
Strengths
- Spelled exactly as it sounds, and short enough that nobody asks twice — a rare combination in a biblical name.
- A documented record stretching from Genesis through Greek and Latin scripture into continuous English use since the Puritans.
- Recognizable in most European languages, which read it with only small adjustments to the ending.
To consider
- The final -th does not exist in Spanish, French, Portuguese or most Asian languages, so the name is often heard and repeated as 'Set' or 'Seth-uh' outside English.
- It resists shortening. Beyond a childhood 'Sethy', there is no nickname waiting, which suits some families and leaves others without an affectionate register.
- The Egyptian god Set is written Seth in older scholarship and shows up that way in mythology books and video games. It is an unrelated name, but the overlap occasionally gets mentioned.
Documented properties of each name — how it spells, travels and shortens — not opinions about the child.
How each is likely to age
Cassius
40%chance Cassius feels dated by 2040
Cassius sits in the calm middle of the cycle — neither chasing a wave nor sliding off one. Middle-of-the-cycle names age slowly and predictably.
Seth
72%chance Seth feels dated by 2040
Seth is coming down from a big peak (#63 in 2000). This is the stretch of the cycle where a name starts to sound like the decade it ruled.
A reading of where each name sits on the long naming cycle — computed, not measured, and explained on the data page.
With your last name
Say both in full. The notes are facts about letters and sound — a rhyme, a shared initial, the monogram — not a verdict on either name.
Type a last name to hear Cassius and Seth in full.
Weighing the whole shortlist? Run the full comparison — up to eight names with your last name, initials, classroom projections and a printable report.
Decide together
Nobody names a baby alone
Still torn between Cassius and Seth?
Put both to the vote.
One link to your partner, your parents, your sister. Each of them gets the two names, a one-tap answer and room to say why — and every reply lands in one place.
Free to start · no account needed · everyone you invite votes in one tap
More than two in the running? Settle it with a bracket or run the full comparison with your last name.
More head-to-heads
Same measures, different pair. Sixty more are dealt daily in the arena.
Lists these names appear on
- Victorian names ready for a second century
- Hero and god names for boys
- Dark academia names with candlelit gravitas
- Ancient Roman names in modern use
- all guides
Where Cassius and Seth each sit in the library — alternatives in the same style, ranked by the same records.
Cassius or Seth — the short answers
- Which is more popular, Cassius or Seth?
- Seth, in 2025: Seth ranked #581 with 505 babies; Cassius ranked #582 with 504 babies.
- Which name is rising faster, Cassius or Seth?
- Neither is rising. Over the last five years Cassius moved down 94 places; Seth moved down 149 places.
- Which is the older name, Cassius or Seth?
- The US record cannot say: both were already in use when it began in 1880.
- How many people are named Cassius and Seth?
- About 9,200 people named Cassius are estimated to be alive in the US today. About 156,000 people named Seth are estimated to be alive in the US today.
- Will there be other Cassiuss or Seths in the classroom?
- Cassius will almost certainly be the only one in school. Seth will almost certainly be the only one in school.
US figures from the Social Security Administration, 1880–2025. Votes are battle voters on this site, not the birth record. Data & methodology
Keep playing
Sixty more head-to-heads are dealt in the arena every day — or line up Cassius, Seth and the rest of your shortlist with your last name in one printable report.
Free to start · no account needed · everyone you invite votes in one tap