Is Rex a boy's or girl's name?

Rex is primarily a boy's name. It is also used as a girl's name, with 141 recorded births.

When was Rex most popular?

Rex reached its peak popularity in 1951 with 1,503 births that year. It is currently ranked #794 in the U.S.

How popular is the name Rex?

Rex is currently ranked #794 in the U.S. (2024). It has been given to 60,160 babies since 1880.

Rex

A familiar Latin name with steady appeal.

Boy's name| Also girlsLatinDeclining Also a pet name

#794▼ 71in 2024

Meaning & Origin

The reigning king.

Rex is a boy's and girl's baby name of Latin origin, the Latin word for "king," making it one of the most direct and powerful royal names in the English-speaking world. It was used as a title for Roman emperors and British monarchs.

Rex has recorded over 60,000 U.S. births, making it one of the more enduring three-letter names for boys. It peaked in the mid-20th century, went quiet, and has been making a confident comeback as parents rediscover punchy vintage names with undeniable authority.

Compare Rex with another name

Popularity Over Time

Rex climbed 139 spots in the last 20 years — from #933 to #794.

Popularity by Decade

Decade-by-decade popularity data for Rex
Decade	Births	Avg Rank	Trend
2020s	1,819	#719	▼
2010s	3,944	#645	▲
2000s	2,048	#931	▲
1990s	1,741	#835	▼
1980s	2,533	#560	▼
1970s	3,360	#448	▼
1960s	8,732	#270	▼
1950s	13,500	#193	▲
1940s	6,669	#233	▲
1930s	5,949	#209	▲
1920s	5,627	#233	▲
1910s	3,253	#253	▲
1900s	497	#294	▲
1890s	305	#335	▲
1880s	183	#468	—

Year-by-Year Data

View complete yearly data(145 years, 1880–2024)

Year-by-year popularity data for the name Rex
Year	Births	Rank	Change
2024	316	#794	-51 (-13.9%)
2023	367	#723	-13 (-3.4%)
2022	380	#697	+1 (0.3%)
2021	379	#699	+2 (0.5%)
2020	377	#683	-33 (-8.0%)
2019	410	#651	-10 (-2.4%)
2018	420	#632	-14 (-3.2%)
2017	434	#607	+11 (2.6%)
2016	423	#633	+49 (13.1%)
2015	374	#680	-15 (-3.9%)
2014	389	#661	-2 (-0.5%)
2013	391	#630	+6 (1.6%)
2012	385	#631	-1 (-0.3%)
2011	386	#618	+54 (16.3%)
2010	332	#704	+29 (9.6%)
2009	303	#756	+29 (10.6%)
2008	274	#801	+38 (16.1%)
2007	236	#875	-16 (-6.3%)
2006	252	#810	+15 (6.3%)
2005	237	#808	+55 (30.2%)

Source: U.S. Social Security Administration. Showing years with 5+ recorded births.

Rex as a Girl's Name

While overwhelmingly a boy's name, Rex has also been given to 141 girls in the U.S. since 1921.

Unranked

Current rank

141

Total births

1961

Peak year

Compare Rex as boy vs girl

Frequently Asked

Can Rex be used for both boys and girls?

Yes, Rex is used for both boys and girls. As a boy's name, it currently ranks #794. As a girl's name, it is not currently in the top rankings.

Rex has two lives

Rex, the baby name

#794boys

60,160 babies

Currently viewing

Last updated May 2026 · Data: U.S. Social Security Administration (1880–2024) · Methodology

Rex