The Big Mac was created by Jim Delligatti, an early Ray Kroc franchisee, who was operating several restaurants in the Pittsburgh area. It was invented in the kitchen of Delligatti's first McDonald's franchise, located on McKnight Road in suburban Ross Township. The Big Mac had two previous names, both of which failed in the marketplace: the Aristocrat, which consumers found difficult to pronounce and understand, and Blue Ribbon Burger. 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. The Big Mac debuted at Delligatti's Uniontown, Pennsylvania restaurant in 1967, selling for 45 cents. It was designed to compete with Big Boy Restaurants' Big Boy hamburger; Eat'n Park was the Pittsburgh area's Big Boy franchisee at the time. The Big Mac proved popular and it was added to the menu of all U.S. restaurants in 1968.

The Big Mac consists of two 1.6 oz (45.4 g) beef patties, "special sauce" (a variant of Thousand Island dressing), iceberg lettuce, American cheese, pickles, and onions, served in a three-part sesame seed bun. On October 1, 2018, McDonalds announced that it would remove all artificial preservatives, flavors, and coloring from the Big Mac.

The Big Mac is known worldwide and is often used as a symbol of American capitalism and decadence. The Economist has used it as a reference point for comparing the cost of living in different countries – the Big Mac Index – as it is so widely available and is comparable across markets. This index is sometimes referred to as Burgernomics.

According to rd.com