Death by boiling is a method of execution in which a person is killed by being immersed in a boiling liquid. While not as common as other methods of execution, boiling to death has been practiced in many parts of Europe and Asia. Due to the lengthy process, death by boiling is an extremely painful method of execution. Executions of this type were often carried out using a large vessel such as a cauldron or a sealed kettle filled with a liquid such as water, oil, tar, or tallow, and sometimes a hook and pulley system. Instances of boiling alive as a legal punishment were quite rare and infrequent compared to other forms of execution, such as drowning.

In England, the use of boiling alive as a method of execution was rare. The ninth statute passed in 1531 (the 22nd year of the reign of King Henry VIII) made boiling alive the prescriptive form of capital punishment for murder committed by poisoning, which by the same Act was defined as high treason. This arose from a February 1531 incident in which the Bishop of Rochester's cook, Richard Roose, gave several people poisoned porridge, resulting in two deaths. A partial confession having been extracted by torture, the sentence was thus imposed by attainder and without benefit of clergy. His execution took place on April 15, 1532, at Smithfield. A contemporary chronicle reports the following:

He roared mighty loud, and divers women who were big with child did feel sick at the sight of what they saw, and were carried away half dead; and other men and women did not seem frightened by the boiling alive, but would prefer to see the headsman at his work.

Boiling to death was employed again in 1542 for a woman, Margaret Davy, who had also used poison. During the reign of Edward VI, in 1547, the 1531 act was repealed.

Numerous people have been boiled to death in Scotland. For example, with the consent of Jon Haraldsson, the "Bloody Earl" of Orkney, the bishop of Caithness, Adam of Melrose, and a monk named Surlo are said to have been boiled to death by angry husbandmen in 1222 over the bishop's aggressive means of collecting tithes. Alexander II is said to have executed upwards of eighty persons as a punishment for killing the bishop and monk, and the earl fled his lands. But according to the Melrose Chronicle, Adam of Melrose was "burned alive", rather than boiled, and Alexander II executed up to 400 for the crime against the clergy.

William de Soules, a nobleman involved in a conspiracy against Robert the Bruce, was reputed to be a sorcerer consorting with evil spirits, and was boiled alive in 1321 at Ninestane Rig. Around 1420, Melville, the sheriff of the Mearns and laird of Glenbervie, who was resented for his strictness, was apprehended by some other nobles and thrown into the kettle. The nobles are said to have each taken a spoonful of the brew afterwards.

Boiling as an execution method was also used for counterfeiters, swindlers and coin forgers during the Middle Ages. In the Holy Roman Empire, for example, being boiled to death in oil is recorded for coin forgers and extremely grave murderers. In 1392, a man was boiled alive in Nuremberg for having raped and murdered his own mother. Coin forgers were boiled to death in 1452 in Danzig and in 1471 in Stralsund. Even as late as 1687, a man in Bremen was boiled to death in oil for having been of valuable help to some coin forgers who had escaped justice.

In the Dutch town of Deventer, the kettle that was used for boiling criminals to death can still be seen.