Billy vs Caius

Baby Name Comparison — 2026

Billy

Boy #1,051 Most Popular 2 Syllables

Meaning

"resolute protector"

Origin: Old German via Norman French

Cultural Roots

English American Australian Irish

Quick Stats

Popularity Rank
#1,051
Total SSA Count
210
Syllables
2
Formality
Casual
Nicknames
Bill, Bills

Playground Safety Score

✓ All Clear
Full profile for Billy →

Caius

Boy #1,063 Most Popular 2 Syllables

Meaning

"to rejoice, joyful"

Origin: Latin

Cultural Roots

Roman British European American

Quick Stats

Popularity Rank
#1,063
Total SSA Count
205
Syllables
2
Formality
Formal
Nicknames
Cai, Kai

Playground Safety Score

✓ All Clear
Full profile for Caius →

Popularity Comparison

Billy Rank #1,051
Caius Rank #1,063

Billy is more popular, ranked #1051 vs #1063 for Caius.

Popularity Over Time

Historical US popularity rank — lower number means more popular.

Middle Name Pairings

Billy ___

  • Billy Ray
  • Billy Joe
  • Billy Dean
  • Billy James
  • Billy Lee
  • Billy Gene

Caius ___

  • Caius James
  • Caius John
  • Caius Edward
  • Caius William
  • Caius Alexander
  • Caius Thomas

Sibling Name Ideas

Names that pair well as siblings.

If you choose Billy

Bobby Tommy Jimmy Johnny Betty

If you choose Caius

Livia Augustus Felix Octavia Marcus

Which Name Fits Your Family?

Answer 3 quick questions and we'll help you decide.

1. Which style feels more like your family?

Frequently Asked Questions

Is Billy or Caius more popular?

Billy is more popular, ranked #1051 compared to Caius at #1063 in the United States.

What do Billy and Caius mean?

Billy means "resolute protector" (Old German via Norman French origin). Caius means "to rejoice, joyful" (Latin origin).

Are Billy and Caius boy or girl names?

Billy is primarily a boy name. Caius is primarily a boy name.

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← Full profile: Billy ← Full profile: Caius Browse all baby names