The Demmin mass suicide was a mass suicide committed by the inhabitants of the town of Demmin, Pomeranian Province (presentday MecklenburgWestern Pomerania, Germany), between April 30 and May 2, 1945. The deaths occurred during the general panic caused by the atrocities committed by Red Army soldiers, who had previously looted the town. Although the number of deaths varies, the Demmin case is known to be the largest recorded mass suicide in the country, being part of the mass suicides carried out among the population of Germany in 1945.

Nazi officers, the Wehrmacht and several civilians had left the town before the arrival of the Red Army, while on the other hand thousands of refugees from the East had sought asylum in Demmin. Three Soviet negotiators were shot before the arrival of the USSR soldiers in the town, against whom the Hitler Youth, among others, opened fire once inside Demmin. The Wehrmacht, during its retreat, had blown up the bridges over the Peene and Tollense rivers, which caused the closure of the city from the north, south and west, blocking the Red Army's advance and trapping in turn the civilians still remaining in Demmin. The Soviets finally sacked and burned the town, committing all kinds of rapes and executions.

Numerous inhabitants and refugees were determined to commit suicide, some of them together with the rest of their families. Suicide methods included drowning in rivers, hanging, slitting their wrists and shooting themselves. Many of the bodies were buried in mass graves and, after the war, suicides became a taboo subject in the German Democratic Republic under the rule of the Socialist Unity Party of Germany.