Spam (stylized in all-caps) is a brand of lunch meat (processed canned pork and ham) made by Hormel Foods Corporation, an American multinational food processing company. It was introduced in the United States in 1937 and gained popularity worldwide after its use during World War II. As of July 5, 2022^[update], Spam is sold in 48 countries, and trademarked in more than 100 countries, on 6 continents.^{[citation needed]}

Spam's main ingredient is a mixture of pork and ham, with salt, water, modified potato starch (as a binder), sugar, and sodium nitrite (as a preservative). Natural gelatin is formed during cooking in its cans on the production line. It is available in different flavors, some using different meats, as well as in "lite" and lower-sodium versions. Spam is pre-cooked, making it safe to consume straight from the can, but it is often cooked further for taste.

Spam has become part of popular culture, including a Monty Python sketch, which repeated the name many times, leading to its name being used to describe unsolicited electronic messages, especially email. It is occasionally celebrated at festivals such as Spamarama in Austin, Texas.

Hormel introduced Spam on July 5, 1937. The Oxford Encyclopedia of Food and Drink in America states that the product was intended to increase the sale of pork shoulder, a cut which did not sell well. Ken Daigneau, the brother of a company executive, won a $100 prize that year in a competition to name the new item. Hormel states that the meaning of the name "is known by only a small circle of former Hormel Foods executives", but a popular belief is that the name is a contraction of "spiced ham". It has also been speculated to be an acronym for "shoulder of pork and ham".

The difficulty of delivering fresh meat to the front during World War II saw Spam become a ubiquitous part of the U.S. soldier's diet. It became variously referred to as "ham that didn't pass its physical", "meatloaf without basic training", and "special army meat". Over 150 million pounds (75,000 short tons) of Spam were received by the military before the war's end. However, several troops grew tired of the product. They expressed their frustrations in written letters to Jay Hormel, the president of the company, about the presence of Spam at every meal. Despite this disparagement, throughout the war, countries ravaged by the conflict and faced with strict food rations came to appreciate Spam.

During World War II and the occupations that followed, Spam was introduced into Guam, Hawaii, Okinawa, the Philippines, and other islands in the Pacific. Immediately absorbed into native diets, it has become a unique part of the history and effects of U.S. influence in the Pacific islands. As a consequence of World War II rationing and the Lend-Lease Act, Spam was sold in the United Kingdom. British Prime Minister Margaret Thatcher later referred to it as a "wartime delicacy". In addition to increasing production for the U.K., Hormel expanded Spam output as part of Allied aid to the Soviet Union. In his memoir Khrushchev Remembers, Nikita Khrushchev declared: "Without Spam, we wouldn't have been able to feed our army."

The billionth can of Spam was sold in 1959, and the eight billionth can was sold in 2012. As of 2026, Hormel states there have been more than nine billion cans sold.

Domestically, Spam's chief advantages were affordability, accessibility, and extended shelf life. Statistics from the 1990s say that 3.8 cans of Spam were consumed every second in the United States, totaling nearly 122 million cans annually. It became part of the diet of almost 30% of American households, perceived differently in various regions of the country. It is also sometimes associated with economic hardship because of its relatively low cost.