Marriott was founded by J. Willard Marriott in 1927 when he and his wife opened a root beer stand in Washington D.C. As a Mormon missionary in the sweltering, humid summers in Washington D.C, Marriott was convinced that what the city needed was a such a place to get a cool drink. They later expanded their enterprises into a chain of restaurants and hotels.

The Key Bridge Marriott in Arlington, Virginia is Marriott International’s longest operating hotel, and celebrated its 50th anniversary in 2009. Their son and current Chairman and Chief Executive Officer, J.W. (Bill) Marriott, Jr. has led the company to spectacular worldwide growth. Today, Marriott International has about 3,400 lodging properties located in the United States and 67 other countries and territories. Edwin D. Fuller is the current President and Managing Director of International Lodging for Marriott International.

Marriott International was formed in 1992 when Marriott Corporation split into two companies, Marriott International and Host Marriott Corporation.

In 2002 Marriott International began a major restructuring by spinning off many Senior Living Services Communities (which is now part of Sunrise Senior Living) and Marriott Distribution Services, so that it could focus on hotel ownership and management. The changes were completed in 2003.

In April 1995, Marriott International acquired a 49% interest in the Ritz-Carlton Hotel Company LLC. Marriott International believed that it could increase sales and profit margins at the Ritz, a troubled chain with a significant number of properties either losing money or barely breaking even. The cost of Marriott's initial investment was estimated to be about $200 million in cash and assumed debt. The next year, Marriott spent $331 million to take over the Ritz-Carlton Atlanta and buy a majority interest in two properties owned by William Johnson, a real estate developer who had purchased the Ritz-Carlton Boston in 1983 and expanded his Ritz holdings over the next twenty years.

The Ritz began expansion into the lucrative timeshare market among other new initiatives made financially possible by the deep pockets of Marriott, which also lent its own in-house expertise in certain areas. There were other benefits for Ritz-Carlton flowing from its relationship with Marriott, such as being able to take advantage of the parent company's reservation system and buying power. The partnership was solidified in 1998 when Marriott boosted its interest in Ritz-Carlton to 99 percent. By 1999 revenues from the 35 hotels it operated around the world totaled about $1.4 billion.

Marriott International owned Ramada International Hotels & Resorts until its sale on September 15, 2004 to Cendant. It is the first hotel chain to serve food that is completely free of trans fats at all of its North American properties.

In 2005, Marriott International and Marriott Vacation Club International comprised two of the 53 entities that contributed the maximum of $250,000 to the second inauguration of President George W. Bush.

On July 19, 2006, Marriott announced that all lodging buildings they operate in the United States and Canada would become non-smoking beginning September 2006. "The new policy includes all guest rooms, restaurants, lounges, meeting rooms, public space and employee work areas."

On November 11, 2010, Announced plans to add over 600 hotel properties by 2015, the bulk of the additions will be in the emerging markets of India, where it plans to have 100 hotel properties and other countries include China and Southeast Asia.