Olivia vs Rex

Baby Name Comparison — 2026

Olivia

Girl #1 Most Popular 4 Syllables

Meaning

"olive tree"

Origin: Latin

Cultural Roots

English Italian American

Quick Stats

Popularity Rank
#1
Total SSA Count
14,718
Syllables
4
Formality
Moderate
Nicknames
Liv, Livvy, Oli

Playground Safety Score

✓ All Clear
Full profile for Olivia →

Popularity Comparison

Olivia Rank #1
Rex Rank #793

Olivia is more popular, ranked #1 vs #793 for Rex.

Popularity Over Time

Historical US popularity rank — lower number means more popular.

Middle Name Pairings

Olivia ___

  • Olivia Rose
  • Olivia Grace
  • Olivia Jane
  • Olivia Mae
  • Olivia Claire
  • Olivia Jade

Rex ___

  • Rex James
  • Rex Oliver
  • Rex Arthur
  • Rex Henry
  • Rex William
  • Rex Theodore

Sibling Name Ideas

Names that pair well as siblings.

If you choose Olivia

Liam Noah Charlotte Emma Sophia

If you choose Rex

Max Leo Augustus Vivienne Cordelia

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 Olivia or Rex more popular?

Olivia is more popular, ranked #1 compared to Rex at #793 in the United States.

What do Olivia and Rex mean?

Olivia means "olive tree" (Latin origin). Rex means "king" (Latin origin).

Are Olivia and Rex boy or girl names?

Olivia is primarily a girl name. Rex is primarily a boy name.

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← Full profile: Olivia ← Full profile: Rex Browse all baby names