Unisex name · since 1927

Si

Since 1927, U.S. Social Security records show 166 babies named Si, peaking in 2013. See the year-by-year trend, decade totals, and state rankings below, sourced from federal birth data.

#14,113 of 45,481
all-time among boys
166
born since 1927
2010s
peak decade

166 boys have been named Si since 1927, though it isn't currently a top-ranked name.

Social Security Administration records show Si recorded 166 times among boys since 1927, though it doesn't currently rank among the most-used boys names, peaking in the 2010s. This profile derives year-by-year birth trends, decade totals, and state-level distribution directly from SSA birth-registration files spanning 1927 to 2017.

  • #14,113 of 45,481 all-time among boys
  • 166 born since 1927
  • 2010s peak decade

Data updated Aug 2026

The verdict

According to the U.S. Social Security Administration, Si ranks #14,113 of 45,481 boys' names by all-time recorded births (highest first). 166 born since 1927, peaking in the 2010s.

#14,113 of 45,481
all-time among boys
166
born since 1927
2010s
peak decade
Below the archive median
All-time archive position

Si's 166 recorded births place it above 68.95% of the 45,481 boys names in the full SSA archive.

National only
State-record footprint

No state rows cleared SSA’s public reporting threshold for this name.

Si's usage pattern, beyond the headline number

Divide Si's SSA record in two at 1998 and the more recent half accounts for 51% of all births, the earlier half the remaining 49%, a genuinely balanced usage pattern. Its calmest year was 1927, with only 5 births recorded -- set against the 2013 peak of 15, that's the full swing in one name's fortunes.

Si popularity over time - boys

Annual U.S. births registered with the Social Security Administration · 1927–2017

Last recorded 2017
Peak year (2013)
15
Annual births at peak, across 91 years of records
05101520 192719501980198719982003200920132017 6

Si popularity over time - girls

19 total births recorded since 2006 (Si as girls' name)

Unisex variant - 19 births
456789 200620072011 8

Si by decade

2010s is the heaviest window (39 births, 23% of the file).

2010s was Si's strongest decade.

39 babies received the name during that ten-year window, about 23% of all-time use.

Si births by decade

Total births in each ten-year window

births

What this shows Peak: 2010s at 39 births (23% of all-time use).

Source U.S. Social Security Administration · Baby Names As of August 2026

Frequently Asked Questions

How popular is the name Si? ▼
Si has been given to 166 babies in the U.S. since 1927, according to SSA data. Its archive ordinal is #14,113 of 45,481 among boys' names (total births, highest first). Its last appearance in the data was 2017. 15 babies were born in 2013, its single highest year.
Where does Si sit in the SSA name archive? ▼
According to the U.S. Social Security Administration, Si ranks #14,113 of 45,481 boys' names by all-time recorded births (highest first). All-time ordinal matches browse popularity (total births DESC); the current ordinal uses the null SSA file. See /methodology#corpus-placement.
When was Si most popular? ▼
Si was most popular in the 2010s decade with 39 total births. The single peak year was 2013.
Is Si a unisex name? ▼
Yes, Si is used for both boys and girls. As a boy's name it has 166 births, and as a girl's name it has 19 births.
How long has the name Si been used? ▼
Si has been recorded in Social Security data since 1927, spanning 91 years of data through 2017.
What names are similar to Si? ▼
Names with a similar sound or spelling include Sidney, Silas, Simon, Sincere, and 4 more. These share a common prefix and are also used for boys.

Keep exploring Si

Nearby Names Like Si

Names with a similar sound, spelling, or feel to Si

Sidney Boy
#1323 84,202 births
Silas Boy
#71 75,465 births
Simon Boy
#230 70,283 births
Sincere Boy
#630 10,095 births
Simeon Boy
#1091 9,462 births

Compare Si side by side: Si vs Sidney Si vs Silas Si vs Simon

Or pick any two names to compare →

Related Names

Names with a similar number of total births

Thos
166 births · Peak 1915
Wing
166 births · Peak 1984
Fleet
166 births · Peak 1930
Liberato
166 births · Peak 1920
Key
166 births · Peak 1993
Verdis
166 births · Peak 1922
Carel
166 births · Peak 1925
Neilan #9817
166 births · Peak 2017

Nationwide names with similar peak year or record span

Two nationwide peer axes for Si: closest SSA peak year, and closest first→latest record span. Distinct from the spelling and current-rank neighborhoods above.

Peak year is the single SSA year with the most births for that name; record span is first-to-latest year in the national files, not a recommendation or shared origin claim.

Data Sources

Data as of August 2026. Source: U.S. Social Security Administration (SSA).

According to the Social Security Administration, this profile draws directly from the agency's public-use baby-name files (updated June 2026). See our methodology for the full extraction, aggregation, and privacy-suppression rules.

Primary: Source: U.S. Social Security Administration, Baby Names from Social Security Card Applications, National Data, 1927–2017 (ssa.gov/oact/babynames).

State-level: Source: U.S. Social Security Administration, Baby Names, State-Level Files (namesbystate.zip).

Name Almanac is rendered directly from the Social Security Administration's public baby-name files, no number is typed in by an editor. This profile for Si draws directly on SSA national and state-level files, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of August 2026.