Treblinka was the second-deadliest extermination camp to be built and operated by Nazi Germany in occupied Poland during World War II. It was in a forest north-east of Warsaw, 4 km (2.5 mi) south of the village of Treblinka in what is now the Masovian Voivodeship. The camp operated between 23 July 1942 and 19 October 1943 as part of Operation Reinhard, the deadliest phase of the Final Solution. During this time, it is estimated that between 700,000 and 900,000 Jews were murdered in its gas chambers, along with 2,000 Romani people. More Jews were murdered at Treblinka than at any other Nazi extermination camp apart from Auschwitz-Birkenau.

Nazi Germany used six extermination camps, also called death camps, or killing centers, in Central Europe during World War II to systematically murder over 2.7 million people – mostly Jews – in the Holocaust. The victims of death camps were primarily murdered by gassing, either in permanent installations constructed for this specific purpose, or by means of gas vans. The six extermination camps were Chełmno, Belzec, Sobibor, Treblinka, Majdanek and Auschwitz-Birkenau. Extermination through labour was also used at the Auschwitz and Majdanek death camps. Millions were also murdered in concentration camps, in the Aktion T4, or directly on site.