Tadeusz

given name · Polish · Latin script

Recorded as a male name· opposite-gender records fall within measured source noise

Tadeusz is a given name, with more bearers in Poland than in any other country, where it is the 57th most common given name. It appears chiefly in Polish and English, written in the Latin script. Recorded meaning: a male given name, equivalent to English Thaddaeus.

rarermore common
  • PLPoland1 in 165
  • CZCzechia1 in 58K
  • GBUnited Kingdom1 in 109K

carrying the name, one hue, darker where it is more common. Hover a country for its figure.

≈237K

across 12 countries

2

recorded for this name

Sources
181

37K records

Official registry-verified

1 in 165

Poland

Spellings & scripts

TadeuszLatin · Polish1.2M records
ТадеушCyrillic · Bulgarian13 records

Locally spelled Тадеуш in RU Russia, BG Bulgaria.

Spellings marked ● are how people bearing the name write it in our records; ○ marks a model's transliteration. Click a spelling to open its page.

Meaning & origin

a male given name, equivalent to English Thaddaeus

Sources 1

  • kaikki.org Wiktionary extract (IPA + transliterations)

Attested across 11 languages in the etymology graph.

Where in the world

Sorted by bearers counted by national registers, records where none counts.

Where Tadeusz is recorded, by country
CountryMost common spellingSources
PL Poland#57232,09516K rec.1 in 165232KTadeusz166
US United States2,69318K rec.1 in 124K2.7KTadeusz181
GB United Kingdom1,9031.3K rec.listedTadeusz74
SE Sweden79636 rec.1 in 13K79619
CA Canada362319 rec.Tadeusz51
NO Norway281141 rec.1 in 19K846Tadeusz15
BR Brazil20613 rec.1 in 1M2292
CZ Czechia18637 rec.1 in 58K186Tadeusz24
SK Slovakia1758 rec.Tadeusz14
IS Iceland1591 in 2.2K159
NL Netherlands141161 rec.1 in 123K141Tadeusz18
IT Italy141134 rec.listedTadeusz16

Roughly 232K people in Poland bear this name (about 1 in 165). Estimates project the name's share of our records onto national population, so each is only as good as the record base beside it — the Basis column gives that base; rows marked rest on fewer records than the estimate itself and are order-of-magnitude at best.

Country figures for a list of names, at full precision, are available under licence rather than by scraping this table. How that works.

Languages

  • Polish1.2M97%
  • English17K1%
  • French5.3K1%
  • German3.2K1%
  • Spanish1.6K1%
Show as table
Languages in which the name is recorded
NameRecordsNote
Polish1,203,87797%
English17,4291%
French5,3111%
German3,2321%
Spanish1,6421%

Language is read off each record's context, not declared by the bearer; a share is of all records for this spelling.

Other names spelled this way

Tadeusz is also recorded as 4 other names, grouped separately because the records behind them do not connect to the one described above.

  • English given name20K records spelled Tadeusz21 spellings in the group

    Most recorded in United States, Germany, United Kingdom, Australia

    Languages: English, German, Dutch

    Also written Thaddaeus, Thaddäus, Thaddaus, Thaddaues, Thäddäus

  • French given name9.1K records spelled Tadeusz6 spellings in the group

    Most recorded in France, United States, Brazil, Spain

    Languages: French, Spanish, Portuguese

    Also written Thaddaeus

  • German given name3.7K records spelled Tadeusz3 spellings in the group

    Most recorded in Germany, United States, Austria, Poland

    Also written Tadeüsz, Tadeuesz

  • Ukrainian given name386 records spelled Tadeusz12 spellings in the group

    Most recorded in Ukraine, Russia, Belarus, Kazakhstan

    Languages: Ukrainian, Russian, Polish

    Also written Тадеуш, Tadeush, Тадэвуш

41 further groups record this spelling and are not listed here.

Grouping is the name graph's, not a register's: two spellings join a group when the evidence links them, so a group is a claim about the records rather than about the people.

Other recorded senses

Tadeusz is also recorded in 2 other lexicons, as a different name or as an ordinary word. These are senses of the spelling, not of the name above.

  • In Polish, Thaddeus

    as a namePolish Personal Names (CIA Foreign Names Studies, ch. 24)

  • Polish form of THADDEUS .

    as a word

Ordered by how much of this spelling's record each language holds, so a sense from a language the name is barely used in sits last rather than first.

Over time

010203019201940196019802000202026 · 1917

Show as table
Tadeusz in SSA — National Baby Names (1880–present), United States, 1912–2024
Yearrecords
19125
19135
19145
191514
191610
191726
191819
191917
192017
192112
192212
192315
19248
192515
19266
192710
19306
19546
19555
19578
19595
196210
19647
196711
19697
19708
19739
19755
19805
19815
19828
19845
19855
19875
19906
19967
19985
20006
20036
20105
20125
20148
20155
20177
20197
20208
20215
202213
20239
20245

US SSA — National Baby Names (1880–present)50 years between 1912–2024. One register's own figures, never a sum across registers: two registers counting the same people would double them.

Notable people with this name

1700180019002000Tadeusz Kościuszko, b. 1746Tadeusz Boy-Żeleński, b. 1874Tadeusz Kotarbiński, b. 1886Tadeus Reichstein, b. 1897Tadeusz Różewicz, b. 1921Tadeusz Borowski, b. 1922Tadeusz Konwicki, b. 1926Tadeusz Mazowiecki, b. 1927Jan Komasa, b. 1981Karol Nawrocki, b. 1983

The ten people covered by the most Wikipedia language editions — a proxy for cross-cultural notability, which favours historical and Western figures over equally prominent contemporary ones — shown by birth year. Source: Wikidata (CC0).

Evidence

Attested in 45 sources across 21 countries.

Official registers attesting Tadeusz
CountryRegisterYearCountRank
PL Polanddane.gov.pl — PESEL given names (first + second name position, 2026-01-20)2026232K#18
PL Polanddane.gov.pl — PESEL living persons (names)192K#33
US United StatesCensus Bureau — First Name Frequency 2020 by sex20202.7K#6,064
NO NorwaySSB — Navnesøk (name-search service, living population)846#1,823
SE SwedenSkatteverket — Sök hur många som har ett visst namn (living population)796#2,000
FR FranceINSEE — Fichier des prénoms (1900–2024)1950795#620
FI FinlandDVV — Nimipalvelu (Finnish name service, per-name lookup)745#1,731
PL PolandMinistry of Digitalization — Imiona nadawane dzieciom w Polsce (2000–present)609
NO NorwaySSB PxWebApi — Persons/Last names by year (StatBank tables 10501/12891)2014399
NO NorwaySSB PxWebApi — Persons/Last names by year (StatBank tables 10501/12891)2013391
NO NorwaySSB PxWebApi — Persons/Last names by year (StatBank tables 10501/12891)2015386
NO NorwaySSB PxWebApi — Persons/Last names by year (StatBank tables 10501/12891)2016377

Reference works 4

  • Dictionary of American Family Names
  • Wikipedia given-name tokens
  • Wikipedia surname tokens
  • Wikidata name items (native-script + romanized given/family names)

These works list the name; their figures are licensed and are not reproduced here.

Register rows as of the 2026-09-12 data build · 318 rows in the corpus for this spelling.

Frequently asked questions

How common is the name Tadeusz?
We estimate roughly 237 thousand people bear Tadeusz (counting its spellings and scripts) across 12 countries in our records.
In which country does Tadeusz have the most bearers?
We estimate about 232 thousand people bear Tadeusz in Poland, more than in any other country in our records, where it is most often spelled tadeusz.
Where is Tadeusz most common?
Tadeusz is densest in Poland, where the national register counts about 1 in 165 people carrying it.
How common is Tadeusz compared with other names?
In Poland, Tadeusz is the 57th most common given name of 66,904 given names recorded there.
Is Tadeusz a male or female name?
Tadeusz is a male name in our records. Opposite-gender entries fall within the cross-gender noise we measure in the source data, so we don't report them as usage.
What does the name Tadeusz mean?
Recorded meaning: a male given name, equivalent to English Thaddaeus
Query this name via API
curl https://api.mondonomo.ai/api/v1/name-graph/tadeusz

The same payload this page is built from: spellings and scripts, countries and languages, related names, and the registers that attest the form. Rate-limited for casual use. Bulk access and licensing.

About this data

measured from records inferred from the name graph machine-generated

Data snapshot . Figures are rebuilt periodically and will change.

Statistics are aggregated from the Mondonomo name corpus; related names and etymology are inferred from the name graph; pronunciation and any machine-marked transliterations are model-generated. Read how the numbers are made, including their known failure modes, and where the data comes from.

Reference works we consult — surname dictionaries, official name registers, Wikidata and Wiktionary — are named directly, beside the claims they support. The per-country source counts also include datasets of person records: we publish how many there are and their authority tier, but not their names.

Cite this page Mondonomo, “Tadeusz” — the 57th most common given name in Poland. Data snapshot 2026-09-12.

See how Tadeusz parses inside a full name →