Despite criticism about its contribution to the obesity epidemic, globalisation and environmental damage, not to mention various beef crises, involvement in the UK's longest-running civil trial and 2004's 'Super Size Me' documentary, McDonald's continues to expand.
It currently has more than 30,000 restaurants serving nearly 50m people in more than 119 countries each day, and its most recent figures showed a 5% rise in sales since the beginning of the year. Today's anniversary is being marked with a restaurant opening in Chicago.
The restaurant chain was born when Ray Kroc invested his life savings to become the exclusive distributor of a milkshake maker called the Multimixer.
Kroc heard of a hamburger stand in California run by Dick and Mac McDonald that ran eight of the Multimixer machines at a time. He visited the store in 1954, and was impressed at the speed at which customers were served, persuading the McDonalds that he should open more restaurants so that he could sell more Multimixers. In 1955 the first McDonald's opened in Des Plaines, Illinois.
Ronald McDonald, the chain's mascot and chief happiness officer, is somewhat younger, having first appeared in 1963. Five years later, McDonald's signature burger, the Big Mac, was introduced, followed in 1973 by the Egg McMuffin and in 1979 by the Happy Meal.
McDonald's did not reach the UK until the 1970s, when families would travel great distances to sample its burgers. The drive is a little less taxing these days with more than 1,000 stores in the UK.
It is seeking to move on from its roots of fries, burgers and shakes, and now sells salads and fresh fruit alongside more traditional items such as Chicken McNuggets. It has signed celebrities like Justin Timberlake and Destiny's Child to feature in its ads, and in 2003 introduced the "I'm lovin' it" strapline.
However, it has been beset over the last two years by the untimely deaths of two consecutive chief executive officers, Jim Cantalupo, who passed away in April 2004, and the Australian Charlie Bell, who died from cancer earlier this year.
It was also forced into crisis PR mode by the documentary 'Super Size Me', in which the director Morgan Spurlock spent 30 days eating nothing but food from McDonald's. The film showed Spurlock putting on weight and undergoing a rapid deterioration in his health.
The original McDonald's restaurant in Illinois is now a museum for McDonald's memorabilia, including the Multimixer. McDonald's is asking former members of staff to submit their memories of working at the chain, as part of its 50th anniversary celebrations.
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