.17 December 1905 – 1 April 2002), often referred to by his nickname, The White Death (Finnish: Valkoinen kuolema; Russian: Белая смерть, romanized: Belaya smert’), was a Finnish military sniper in World War II during the 1939–1940 Winter War against the Soviet Union. He used a Finnish-produced M/28-30 (a variant of the Mosin–Nagant rifle) and a Suomi KP/-31 submachine gun. He is believed to have killed over 500 enemy soldiers during the Winter War, the highest number of sniper kills in any major war. Because of this, he is often regarded as the deadliest sniper of all time.

Häyhä estimated in his private war memoir that he shot around 500 Soviet soldiers. The memoir, titled Sotamuistoja (War memoirs), was written in 1940, a few months after he was wounded, and described his experiences in the Winter War from 30 November 1939 to 13 March 1940. Hidden for decades, the memoir was discovered in 2017.