The Leo surname
In the 2010 U.S. Census, 8,039 people carried this name — #4,423 among all U.S. surnames, about 1 in every 36,600 people counted. That is up 5% from 7,638 in 2000.
In Argentina’s national register
At least 809 people named Leo live in Argentina.
RENAPER only publishes a name in a province when more than ten people there share it, so the real number is higher. Most of them live in Buenos Aires Province.
Where it concentrates, on the mapWhere they live today
RENAPER (National Registry of Persons, Argentina), surnames of residents by province, December 2021 — CC BY 4.0.
In Switzerland’s population statistics
424 people named Leo live in Switzerland.
They live in 18 of Switzerland’s 26 cantons, most of all in Zurich.
Where it concentrates, on the mapWhere they live today
Swiss Federal Statistical Office (FSO), «Surnames of the permanent resident population by canton», 2025, opendata.swiss/en/dataset/nachnamen-der-standigen-wohnbevolkerung-nach-kanton3 · names with fewer than 3 bearers in a canton are not published.
In France’s civil register
France’s register of deaths holds 381 people named Leo.
149 of them were born outside France. Those born in France came from 36 départements, most often Côtes-d’Armor.
Where it concentrates, on the mapWhere they were born
Fichier des personnes décédées, INSEE — Licence Ouverte 2.0 · deaths recorded in France since 1970, by place of birth.
In Ireland’s birth registers, 1890
Ireland registered 5 births for the Leo name in 1890.
Most were registered in Munster. By the Registrar-General’s own method — births multiplied by 44.38 — that is about 200 people bearing the name in Ireland at the time. The Registrar-General’s note on the name: “All in Limerick.”
Too few records to say where it concentrates region by region — these are plain counts, not shares.
Where they were born, 1890
Registrar-General for Ireland, «Special Report on Surnames in Ireland» (R. E. Matheson, 1894), births index of 1890 — public domain.
In Belgium’s population register
At least 98 people named Leo live in Belgium.
Statbel only publishes a name in a municipality when five or more people there share it, so the real number is higher. Most of them live in Flemish Brabant.
Too few records to say where it concentrates region by region — these are plain counts, not shares.
Where they live today
Statbel (Statistics Belgium), family names of the population by municipality, 1 January 2026 — CC BY 4.0.
In Poland’s population register
69 people named Leo have a registered home in Poland.
Of the 102 in Poland’s national register, these are the ones with a permanent address on file. They live in 7 of Poland’s 16 voivodeships, most of all in Masovian.
Too few records to say where it concentrates region by region — these are plain counts, not shares.
Where they live today
PESEL register, Ministry of Digital Affairs of Poland (dane.gov.pl) — CC0 · living people by voivodeship of permanent residence, 20 January 2026.
In the Nordic population registers
761 people named Leo are counted in Sweden and Finland.
Sweden’s figure is from 31 December 2022, the last count Statistics Sweden published. Finland counts its citizens, at home or abroad.
Counted, by country
Own calculations based on data from Statistics Sweden (SCB), surnames with at least two bearers, 31 December 2022 — CC BY 4.0 (names with 20 or more bearers shown) · Digital and Population Data Services Agency (DVV), Finland, surname statistics, August 2026 — CC BY 4.0.
In print
Leo in American newspapers,
1882–1924.
Chronicling America, Library of Congress — digitised newspapers in the public domain · 1,273,375 pages in all carry the name.
Who carried it
People named Leo,
with a public archive behind them.
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Brother Leo 1195–1271 · writer -
Marquard Leo d. 1633 · Catholic theologian
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Felicitas Leo d. 1916 · poet
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Garry Leo d. 2026 · police officer
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Francesco de Leo d. 1562 · Catholic priest
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Heinrich Leo d. 1658 · preacher
Wikidata and Wikimedia Commons (CC0) · 10 lives in all are documented under this name.
Nearby in the index
Surnames next to Leo.
- Lentini 2,677 · U.S. census
- Lentz 15,126 · U.S. census
- Leny 103 · U.S. census
- Lenz 11,191 · U.S. census
- Lenzi 1,232 · U.S. census
- Lenzini 183 · U.S. census
- Leon 86,363 · U.S. census
- Leonard 91,475 · U.S. census
- Leonardi 1,834 · U.S. census
- Leonardo 6,007 · U.S. census
- Leonce 233 · U.S. census
- Leoncini 118 · U.S. census
When the index is not enough
This page says where Leo is.
A volume says what happened to it.
Every page in the index is free and stays free. The Heritage Volume is the long form: the full paper trail, the arms, the crossing — bound, and yours.