The Janczak surname
In the 2010 U.S. Census, 685 people carried this name — #33,343 among all U.S. surnames, about 1 in every 434,800 people counted. That is up 4% from 657 in 2000.
In Poland’s population register
7,629 people named Janczak have a registered home in Poland.
Of the 8,322 in Poland’s national register, these are the ones with a permanent address on file. They live in all 16 of Poland’s voivodeships, most of all in Greater Poland.
Where it concentrates, on the mapWhere 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 France’s civil register
France’s register of deaths holds 126 people named Janczak.
57 of them were born outside France. Those born in France came from 14 départements, most often Pas-de-Calais.
Too few records to say where it concentrates region by region — these are plain counts, not shares.
Where they were born
Fichier des personnes décédées, INSEE — Licence Ouverte 2.0 · deaths recorded in France since 1970, by place of birth.
In the Nordic population registers
20 people named Janczak is counted in Sweden.
Sweden’s figure is from 31 December 2022, the last count Statistics Sweden published.
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).
Who carried it
People named Janczak,
with a public archive behind them.
-
Louis Janczak 1896– · politician
-
Waleria Janczak 1903–1959 · pharmacist
-
Wojciech Janczak 1912–1945
-
Jan Henryk Janczak 1916–2016 · film actor
-
Leon Janczak 1922–2009 · politician
-
Julian Karol Janczak 1931–2001 · historian
Wikidata (CC0) · 10 lives in all are documented under this name.
Nearby in the index
Surnames next to Janczak.
When the index is not enough
This page says where Janczak 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.