The Ringelblum Archive is a collection of documents from the World War II Warsaw Ghetto, collected and preserved by the group known under code name Oyneg Shabbos (in Modern Israeli Hebrew: Oneg Shabbat, Hebrew: עונג שבת‎), led by Jewish historian Dr. Emanuel Ringelblum. The group, which included historians, writers, rabbis and social workers, was dedicated to chronicling life in the Ghetto during the German occupation. They worked as a team, collecting documents and soliciting testimonies and reports from dozens of volunteers of all ages. The materials submitted included essays, diaries, drawings, wall posters and other materials describing life in the Ghetto. The collection work started in September 1939 and ended in January 1943.

Today the discovered part of the collection, which contains about 6,000 documents (about 35,000 pages), is housed at the Jewish Historical Institute in Warsaw.

The name Oneg Shabbat means joy of the Sabbath in Hebrew and usually refers to a celebratory gathering held after Sabbath services, often with food, singing, study, discussion, and socializing. This name was selected because the group tended to meet on Shabbat to discuss the progress of their collection and documentation efforts. The form Oyneg Shabbos is Ashkenazic pronunciation.

The members of Oyneg Shabbos initially collected the material with the intention that they would write a book after the war about the horrors they had witnessed. As the pace of deportations increased, and it became clear that the destination was the Treblinka death camp and few Jewish Varsovians were likely to survive, Ringelblum had the archives stored in three milk cans and ten metal boxes, which were then buried in three places in the Ghetto. Two of the canisters, containing thousands of documents, were unearthed on 18 September 1946 and a further ten boxes on 1 December 1950. The third cache is rumored to be buried beneath what is now the Chinese Embassy in Warsaw but a search in 2005 failed to locate the missing archival material.

On January 19, 1942, an escaped inmate from the Chelmno extermination camp, Jacob Grojanowski, reached the Warsaw Ghetto, where he gave detailed information about the camp to the Oneg Shabbat group. His report, which became known as the Grojanowski Report, was smuggled out of the ghetto through the channels of the Polish underground, reached London and was published by June.

All but three members of the Oyneg Shabbos were murdered in the genocides. Emanuel Ringelblum escaped the ghetto, but continued to return to work on the archives. In 1944 Ringelblum and his family were discovered and were executed along with those who hid them. After the war, Rokhl Auerbakh, one of the three surviving members of Oyneg Shabes, initiated the search for and excavation of the buried chronicles.

In 1999, the Emanuel Ringelblum Archives were listed on the Memory of the World Register by UNESCO.

A catalog of the Ringelblum Archive was published in book form in 2009 by the United States Holocaust Memorial Museum and the Jewish Historical Institute, Warsaw; and the entire archive is also available to researchers in digital format at both institutions. The Jewish Historical Institute has published a book series of 10 volumes summarizing parts of the archive as follows: (1) Letters concerning the Holocaust (2) Children — covert teaching in the Warsaw Ghetto (3) Accounts from Kresy (4) Life and work of Gela Seksztajn (5) The Warsaw Ghetto (6) The General Governatore (7) Legacies (8) Territories annexed to the Reich (9) Territories annexed to the Reich (10) Fate of Jews from Łódź (1939–1942).

In 2007, historian Samuel Kassow published Who Will Write Our History? Emanuel Ringelblum, the Warsaw Ghetto, and the Oyneg Shabbes Archive listing all accounts of the Oyneg Shabes archives that have been found.