Sosnowiec Ghetto or Sosnowitz Ghetto was a ghetto established for Jews by Nazi German authorities in the Province of Upper Silesia in occupied Poland during the Holocaust.

Before the war, there were about 30,000 Jews in Sosnowiec, making up about 20% of the town's population. Over the next few years Germans would resettle Jews from smaller local communities to Sosnowiec, temporarily increasing the Jewish community size to 45,000. By late 1942, Będzin and nearby Sosnowiec, which bordered Będzin, became the only two towns in the Zagłębie Dąbrowskie region that were still inhabited by Jews.

The city, located on the pre-war Polish-German border, was taken over by Germans within the first days of the invasion of Poland. Local Jews were rounded up and terrorized immediately; shootings and first mass executions followed soon afterward, and forced relocations, slowly creating a ghetto. On September 9, the Great Synagogue in Sosnowiec was burned.

Judenrat and Jewish police were soon established; the head of the Sosnowiec Judenrat was Moishe Merin (Mojżesz Merin). In the first months of 1940 the Zentrale der Judischen Altestenrate in Oberschlesien (Central Office of the Jewish Councils of Elders in Upper Silesia), headed by Merin, was created in Sosnowiec, representing about 45 communities. For a time, Merin became infamous as the dictator of the Jews of the Zaglebie region, with the power of life and death over local Jews. A local labor camp was established, along with various workshops, overseen by Germans (see Forced labor in Germany during World War II).

Sosnowiec [sɔˈsnɔvʲɛt​͡s] ( listen) is a city in Zagłębie Dąbrowskie, western Lesser Poland in southern Poland, near Katowice. It is one of the central districts of the Upper Silesian Metropolitan Union - a metropolis with a combined population of over two million people located in the Silesian Highlands, on the Brynica river (tributary of the Vistula).

It is situated in the Silesian Voivodeship since its formation in 1999. Previously (since 1945), it was part of Katowice Voivodeship, and before World War Two, Sosnowiec belonged to Kielce Voivodeship. Sosnowiec is one of the cities of the 2.7 million person conurbation - Katowice urban area and within a greater Silesian metropolitan area populated by about 5,294,000 people. The population of the city is 220,450 (June 2009). The city, despite its proximity to Katowice, is not part of Silesia, but belongs to historical Polish province of Lesser Poland.

Its name comes from Polish sosna, referring to the pine forests which were common prior to 1830. It was originally known as Sosnowice. Other variations of the name include Sosnowietz, Sosnowitz, Sosnovitz (Yiddish), Sosnovyts, Sosnowyts, Sosnovytz, Sosnowytz, Sosnovetz, Сосновець Sosnovets (Ukrainian). There are 5 other smaller towns in Poland also called Sosnowiec. They are located in the regions of Kielce, Łódź, and Opole.