The Big Mac is a brand of hamburger sold by the international fast food restaurant chain McDonald's.

It was introduced by a Greater Pittsburgh area franchisee in 1967 and expanded nationwide in 1968, and is widely regarded as the company's flagship product.

The hamburger features a three-slice sesame-seed bun containing two beef patties, one slice of cheese, shredded lettuce, pickles, minced onions, and a Thousand Island-type dressing advertised as "special sauce."

[6] The Big Mac debuted at the McDonald's owned by Delligatti in Uniontown, Pennsylvania, on April 22, 1967,[7] selling for US$0.45 (equivalent to $4.11 in 2023).

The third name, Big Mac, was created by Esther Glickstein Rose, a 21-year-old advertising secretary who worked at McDonald's corporate headquarters in Oak Brook, Illinois.

[21] In 1974 McDonald's commissioned an advertising jingle which popularized the list of ingredients of the Big Mac: "Two all-beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun.

The revival included the original prize of a free Big Mac if the customer was able to recite the slogan in under four seconds.

[24] McDonald's sued the Irish fast-food chain Supermac's for trademark infringement and claimed the name would confuse consumers in European markets.

[25] On 11 January 2019, the European Union Intellectual Property Office (EUIPO) ruled in Supermac's favor in what has been called a "David vs. Goliath" victory.

[27] Supermac's responded by bringing the case to the European Court of Justice, which finally ruled in 2024 that McDonald's had not proven use of the Big Mac trademark when it came to poultry products or operating restaurants.

In 2007, Danya Proud, a McDonald's spokeswoman, said that in the United States alone, 560 million Big Macs are sold each year.