On 1 May 1945, hundreds of people killed themselves in the town of Demmin, in the Province of Pomerania (now in Mecklenburg-Vorpommern), Germany. The suicides occurred during a mass panic that was provoked by atrocities committed by soldiers of the Soviet Red Army, who had sacked the town the day before. Although death toll estimates vary, it is acknowledged to be the largest mass suicide ever recorded in Germany. The suicide was part of a mass suicide wave amongst the population of Nazi Germany.

Nazi officials, the police, the Wehrmacht and many citizens had left the town before the arrival of the Red Army, while thousands of refugees from the East had also taken refuge in Demmin. Three Soviet negotiators were shot prior to the Soviet advance into Demmin and Hitler Youth, amongst others, fired on Soviet soldiers once inside the town. The retreating Wehrmacht had blown up the bridges over the Peene and Tollense rivers, which enclosed the town to the north, west and south, thus blocking the Red Army's advance and trapping the remaining civilians. The Soviet units looted and burned down the town, and committed rapes and executions.

Numerous inhabitants and refugees then killed themselves, with many families doing so together. Methods of suicides included drowning in the rivers, hanging, wrist-cutting, and shooting. Most bodies were buried in mass graves, and after the war, discussion of the mass suicide was taboo under the East German Communist government.