On 9 September 1939, Wejherowo was captured by the Wehrmacht. After the invasion of Poland, which marked the beginning of World War II, Wejherowo was annexed by Nazi Germany and was administered as part of Regierungsbezirk Danzig in the province of Reichsgau Danzig-West Prussia. Most of the town's Jewish community was murdered by the Nazis during the occupation, while many local Poles were also victims of the Nazi extermination policy.