Theo

#5,722 for girls in 2025, 21 births · #82 for boys in 2025, 3,945 births
Given to boys 91.1% of the time

Showing
Show data for
Peak · boys
#78
2023 · 4,140 births
Debut · boys
1880
9 births
In top 100 · boys
4 yrs
of 146 years
Total births · boys
35,830
since 1880

Theo over time

girlsboys

Rank within each sex, plotted together. Click any year to open it.

#1#10#100#1,000#10,000rank188019001920194019601980200020201966peak #512, 1887girlsboysat peak
Hover or use arrow keys to read values by year; click or press Enter to open that year.

Gaps mean fewer than 5 babies received the name that year, so the SSA doesn't publish it.

Show data table
Yeargirlsboys
rankbirthsrankbirths
2025#5,72221#823,945
2024#4,47331#804,129
2023#3,64042#784,140
2022#3,22050#983,642
2021#2,67464#1422,703
2020#3,45044#1722,225
2019#4,43731#1952,018
2018#12,4647#2431,554
2017#12,7137#2901,232
2016#9,41111#354952
2015—#405765
2014—#509550
2013—#663365
2012—#790287
2011—#863245
2010—#914221
2009—#1,032187
2008—#1,019188
2007—#1,012191
2006—#1,116156
2005—#1,150139
2004—#1,172133
2003—#1,291109
2002#15,4325#1,34698
2001—#1,46084
2000—#1,282101
1999—#1,48976
1998—#1,64263
1997—#1,62862
1996—#1,74053
1995—#1,62356
1994—#1,66454
1993—#1,72150
1992—#1,51059
1991#13,1475#1,45261
1990—#1,37066
1989—#1,21977
1988—#1,14577
1987—#1,10675
1986—#1,00385
1985—#1,05776
1984—#2,23223
1983—#1,95527
1982—#1,73433
1981—#1,81131
1980—#1,61936
1979#9,0106#1,53238
1978—#1,35246
1977—#1,24551
1976—#1,11158
1975#7,9846#1,11457
1974—#1,54632
1973—#1,69627
1972—#1,72126
1971—#1,86223
1970#6,3627#1,61528
1969#7,4715#1,49229
1968—#1,61424
1967—#1,41129
1966#5,8096#1,61323
1965—#1,14443
1964#3,69213#1,23639
1963#4,8968#1,37532
1962#3,78212#1,54626
1961#3,18916#1,32236
1960#5,1687#1,21042
1959#4,6258#1,30236
1958#3,74711#1,30535
1957#2,56320#1,27837
1956#3,69611#1,21839
1955#2,28023#1,31333
1954#2,77916#1,38230
1953#2,51618#1,30433
1952#2,50218#1,15241
1951#2,39118#1,05246
1950#1,67931#1,10541
1949#2,06922#1,18536
1948#1,62133#1,02347
1947#1,60235#1,15939
1946#1,58331#1,04543
1945#1,08053#92748
1944#1,57827#97444
1943#1,44233#84661
1942#1,63026#99145
1941#1,31034#1,04039
1940#1,31332#1,05038
1939#1,42427#75464
1938#1,80519#76464
1937#1,25533#1,00040
1936#1,32130#69073
1935#1,11939#72571
1934#1,13339#84555
1933#1,12339#77562
1932#1,11641#70876
1931#1,07443#64385
1930#99355#64590
1929#84271#72175
1928#94762#65292
1927#1,00058#592109
1926#76390#614104
1925#727102#64198
1924#705111#65397
1923#84575#66892
1922#720102#617109
1921#74796#611107
1920#72998#64097
1919#666109#63392
1918#702105#66487
1917#73591#62989
1916#69298#59396
1915#66798#60191
1914#72064#54681
1913#74150#55062
1912#68953#56850
1911#72236#53331
1910#79429#46135
1909#58044#55822
1908#79124#40334
1907#68031#42929
1906#70727#56817
1905#60034#46323
1904#61231#40127
1903#60729#50518
1902#54535#41524
1901#74719#45318
1900#78022#68014
1899#81416#66110
1898#65025#52316
1897#56728#65211
1896#63524#64112
1895#60725#55614
1894#71917#59412
1893#66219#61511
1892#55425#7489
1891#57221#56411
1890#79112#56612
1889#60018#7228
1888#61217#7049
1887#51219#58310
1886#57215#6948
1885#65811#7008
1884#52016#7647
1883#7547#47914
1882#59610#54012
1881#6238#6538
1880#6797#6409
First appearance
1880

In the first year the SSA published name data, Theo was already there! It came in at #640, and was given to 9 baby boys.

Quietest stretch: 1884–1889, when fewer than 11 boys a year got the name.

Where Theo is popular in 1966

No state had 5 or more boys named Theo in 1966, so the SSA doesn't publish it for any state.

See more about Theo
Momentum · boys
Rising
  • 2 spots since 2024 (#80 → #82)
  • 90 spots since 2020 (#172 → #82)
  • 323 spots since 2015 (#405 → #82)
  • Biggest jump: 236 spots in 1938 (#1,000 → #764)
  • Biggest drop: 310 spots in 1937 (#690 → #1,000)
Rise & fade · boys
143 yrs to peak
  • Debuted 1880
  • Peaked 2023 at #78 (4,140 births)
  • Not yet halved from its peak
Top of the charts · boys
Top 100 for 4 yrs
  • Top 10: never
  • Top 100: 4 yrs · run 2022–2025
  • Top 1,000: 80 yrs · run 1880–1939
Share of babies · boys
1 in 413
  • Highest: 1 in 413 boys born in 2023 were named Theo (0.24%)
  • Latest: 1 in 433 boys born in 2025 (0.23%)
Era · boys
The 2020s
  • 58.0% of all boys named Theo (20,784) were born in this decade
Girls or boys?
Flipped in 1946
  • Mostly girls until 1945, mostly boys since
all girlsall boys
Show by decade
DecadeBirthsBest rankAvg rank
1880s93#479 (1883)#648
1890s118#523 (1898)#612
1900s226#401 (1904)#488
1910s714#461 (1910)#578
1920s980#592 (1927)#641
1930s680#643 (1931)#755
1940s440#846 (1943)#1,024
1950s371#1,052 (1951)#1,241
1960s323#1,144 (1965)#1,396
1970s386#1,111 (1976)#1,479
1980s540#1,003 (1986)#1,488
1990s600#1,370 (1990)#1,584
2000s1,386#1,012 (2007)#1,188
2010s8,189#195 (2019)#523
2020s20,784#78 (2023)#109

All figures count published births only (names given to at least 5 boys in a year). Registrations before 1937 are incomplete, so early shares and totals run low.

Theo in 1966

girls
#5,809
6 births · 1 in 282,030 girls
boys
#1,613
23 births · 1 in 77,542 boys

Top girls' names in 1966

  1. #1Lisa56,918
  2. #2Kimberly32,232
  3. #3Mary28,890
  4. #4Michelle27,159
  5. #5Karen25,450
  6. #6Susan23,776
  7. #7Patricia20,112
  8. #8Tammy18,621
  9. #9Angela18,532
  10. #10Jennifer18,215
  11. #5,809Theo6

Top boys' names in 1966

  1. #1Michael79,985
  2. #2David66,408
  3. #3James65,163
  4. #4John65,016
  5. #5Robert59,317
  6. #6William38,237
  7. #7Mark34,801
  8. #8Richard34,457
  9. #9Jeffrey30,200
  10. #10Thomas29,003
  11. #1,613Theo23
More about 1966

girls

1,692,177 girls got a published name in 1966; 1 in 282,030 of them was named Theo, which outranked 23.8% of the 7,624 girls' names that year. The ten most popular names covered 16.0% of girls (24.6% in 1880, 7.0% in 2025).

Ranked beside Theo
  1. #5,273Yolandia7
  2. #5,273Zeola7
  3. #5,273Zora7
  4. #5,809Theo6
  5. #5,809Adine6
  6. #5,809Adrienna6
  7. #5,809Aggie6
  8. #6,564Abra5
  9. #6,564Acquanetta5
  10. #6,564Adana5

Tied with 754 names at #5,809; 3 shown. Tied names share a rank, as in SSA's lists.

Biggest movers since 1965
Risers
  1. ↑ 6,121Tabatha#6,539 → #418
  2. ↑ 1,469Tabitha#1,993 → #524
  3. ↑ 1,325Joell#2,247 → #922
  4. ↑ 1,047Tatia#1,715 → #668
  5. ↑ 969Nichole#1,829 → #860
Fallers
  1. ↓ 398Barb#815 → #1,213
  2. ↓ 310Jewell#952 → #1,262
  3. ↓ 288Roxie#944 → #1,232
  4. ↓ 284Aretha#818 → #1,102
  5. ↓ 280Kecia#392 → #672

Among names in the top 1,000 of either year.

boys

1,783,461 boys got a published name in 1966; 1 in 77,542 of them was named Theo, which outranked 64.5% of the 4,540 boys' names that year. The ten most popular names covered 28.2% of boys (44.2% in 1880, 8.0% in 2025).

Ranked beside Theo
  1. #1,580Vincente24
  2. #1,580Waverly24
  3. #1,580Zack24
  4. #1,613Theo23
  5. #1,613Ahmed23
  6. #1,613Amado23
  7. #1,613Brannon23
  8. #1,650Alfonza22
  9. #1,650Augusto22
  10. #1,650Bailey22

Tied with 36 names at #1,613; 3 shown. Tied names share a rank, as in SSA's lists.

Biggest movers since 1965
Risers
  1. ↑ 1,207Jarrod#1,720 → #513
  2. ↑ 893Heath#1,254 → #361
  3. ↑ 467Illya#1,294 → #827
  4. ↑ 419Jarrett#1,294 → #875
  5. ↑ 399Reynold#1,360 → #961
Fallers
  1. ↓ 464Quint#986 → #1,450
  2. ↓ 303Dario#934 → #1,237
  3. ↓ 299Darran#1,000 → #1,299
  4. ↓ 281Artie#897 → #1,178
  5. ↓ 268Daryn#716 → #984

Among names in the top 1,000 of either year.

See the top 100 for 1966 →