Marriott International, Inc. (NASDAQ: MAR) is an American multinational diversified hospitality company that manages and franchises a broad portfolio of hotels and related lodging facilities. Founded by J. Willard Marriott, the company is now led by his son, Executive Chairman Bill Marriott, and President and Chief Executive Officer Arne Sorenson.

Marriott International is headquartered in Bethesda, Maryland, in the Washington, DC metropolitan area. It has more than 5700 properties in over 110 countries and territories around the world, over 1.2 million rooms (as of September 2016), and additional 195,000 rooms in the development pipeline. In 2017, Marriott was ranked #33 on Fortune's "100 Best Companies to Work For" list, its twentieth appearance on the list.

Marriott was founded by John Willard Marriott in 1927 when he and his wife, Alice Sheets Marriott, opened a root beer stand in Washington, D.C. As a Mormon missionary in the humid summers in Washington, D.C, Marriott was convinced that what residents of the city needed was a place to get a cool drink. The Marriotts later expanded their enterprise into a chain of Hot Shoppes restaurants and the company went public in 1953 as Hot Shoppes, Inc.

The company opened its first hotel, the Twin Bridges Marriott Motor Hotel, in Arlington, Virginia, in 1957. Their second hotel, the Key Bridge Marriott in the Rosslyn neighborhood of the same city, is Marriott International’s longest continuously operating hotel, and celebrated its 50th anniversary in 2009. Their son, J.W. (Bill) Marriott, Jr., led the company to spectacular worldwide growth during his more than 50-year career. In March 2012, at age 80, he turned the CEO responsibilities over to Arne Sorenson, while he assumed the title of Executive Chairman.

Hot Shoppes, Inc. was renamed the Marriott Corporation in 1967.

The company opened two theme parks in 1976. One Marriott's Great America was located outside Chicago, the other Marriott's Great America was located outside San Francisco. Marriott sold both properties in 1984.

Marriott International was formed in 1993 when the Marriott Corporation split into two companies, Marriott International and Host Marriott Corporation. In 1995, Marriott was the first hotel company worldwide to offer guests the option to book reservations online, via the company's implementation of MARSHA (Marriott's Automatic Reservation System for Hotel Accommodations).

In April 1995, Marriott International acquired a 49% interest in Ritz-Carlton Hotel Company LLC. Marriott International believed that it could increase sales and profit margins for The Ritz-Carlton, a troubled chain with a significant number of properties either losing money or barely breaking even. The cost to Marriott was estimated to have been 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-Carlton holdings over the next twenty years.

The Ritz-Carlton began expansion into the lucrative timeshare market and undertook 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 acquired a majority ownership of The Ritz-Carlton. Today, there are 81 Ritz-Carlton properties around the world.

The Marriott World Trade Center was destroyed during the September 11, 2001 attacks.

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.

Marriott International owned Ramada International Hotels & Resorts until its sale on September 15, 2004 to Cendant.

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 it operated 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."

There were bombings at the Islamabad Marriott in 2008 and at the Jakarta Marriott in 2009.

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

On January 21, 2011, Marriott said that pornography would not be included in the entertainment offered at new hotels, which will use an internet-based video on demand system.

On December 13, 2011, J.W. Marriott, Jr. announced he would be stepping down as CEO of the company, while assuming the role of executive chairman. It was announced that Arne Sorenson would be taking over as CEO as of March 2012.

U.S. Republican presidential candidate Mitt Romney released his 2011 federal income taxes on September 21, 2012, showing that he declared $260,390 in director's fees from Marriott International, despite the fact that news was released on January 13, 2011, that he had already stepped down from the Marriott International board to run for president. His had released 2010 tax returns showed earnings in 2010 of $113,881 in director's fees from Marriott. In February 2012, Bloomberg reported on Romney's years overseeing tax matters for Marriott, which had included several "scams" (quoting Sen. John McCain) and legal actions brought against Marriott, which Marriott lost in court, over its manipulations of the U.S. Tax Code.

In December 2012, Guinness World Records recognized the five-star JW Marriott Marquis Hotel Dubai as the world's tallest hotel.

On October 3, 2014 the US Federal Communications Commission (FCC) fined Marriott $600,000 for unlawful use of a "containment" feature of a Wi-Fi monitoring system to deliberately interfere with client-owned networks in the convention space of its Gaylord Opryland Resort & Convention Center in Nashville. The scheme disrupted operation of clients' mobile telephone hotspots by sending fraudulent Wi-fi de-authentication packets. Marriott International, Inc., the American Hotel and Lodging Association and Ryman Hospitality Properties responded by unsuccessfully petitioning the FCC to change the rules to allow them to continue the wilful jamming of client-owned networks, a position which they were forced to abandon in early 2015 in response to backlash from clients, mainstream media, major technology companies and national mobile carriers. The incident drew unfavorable publicity to Marriott's practice of charging transient lodgers $13–15/day for wi-fi connections, routinely included in the base price at most discount chains, and to exorbitant wi-fi fees (typically $250–1000 per device) charged to convention-goers at a time when the $2.25 billion annually in ever-increasing "incidental fees" charged by US-based hotels to their lodgers was already drawing criticism and negative media coverage.

On January 27, 2015, Marriott acquired Canadian hotel chain Delta Hotels. Delta operates 40 hotels in Canada.

On November 16, 2015, Marriott announced the acquisition of Starwood Hotels and Resorts Worldwide for $13 billion. A competing offer for Starwood at $14 billion from a consortium led by China's Anbang Insurance Group was announced March 3, 2016, moving Starwood to cease the deal with Marriott and pursue the offer from Anbang Insurance Group. After Marriott raised its bid to $13.6 billion on March 21, Starwood terminated the Anbang agreement and proceeded again with the merger with Marriott. Following all necessary regulatory approvals in the United States and around the world over the course of 2016, Marriott closed the merger with Starwood on September 23, 2016, creating the world's largest hotel company with over 5700 properties, 1.1 million rooms, and a new portfolio of 30 brands.

The Starwood acquisition gives Marriott a larger non-US presence; approximately 75% of Starwood’s revenues are from foreign markets. The acquisition is the largest of its sort since 2007, when Blackstone acquired Hilton for $26 billion. There is a $400 million breakup fee if the transaction is not completed. Executives noted that total transaction and integration expenditures may exceed $100 million.

Marriott is the first hotel chain to serve food that is completely free of trans fats at all of its North American properties.

The hotel is noted for providing copies of the Book of Mormon in addition to the Holy Bible in its rooms.

As of September 23, 2016, Marriott operates 30 brands internationally.

Marriott developed three theme parks, of which two theme parks were opened. They operated as Marriott's Great America from 1976 until 1984. The parks were located in Gurnee, Illinois; Santa Clara, California; and a proposed but never-built location in the Washington, DC area, and were themed celebrating American history. The American-themed areas under Marriott's tenure of ownership included "Carousel Plaza" (the first section beyond the main gates); small-town-themed "Hometown Square"; "The Great Midwest Livestock Exposition At County Fair" with a Turn of the Century rural-fair theme; "Yankee Harbor", inspired by a 19th-century New England port; "Yukon Territory," resembling a Canadian/Alaskan logging camp; and the French Quarter-modeled "Orleans Place". At opening, the parks had nearly identical lay-outs.

In 1984, Marriott disposed of its theme park division; both parks were sold and today are associated with national theme park chains. The Gurnee location was sold to Six Flags Theme Parks where it operates today as Six Flags Great America. The Santa Clara location was sold to the City of Santa Clara, who retained the underlying property and sold the park to Kings Entertainment Company, renamed Paramount Parks in 1993. From 1993 to 2006, the Santa Clara location was known as Paramount's Great America. In 2006, Paramount Parks was acquired by Cedar Fair Entertainment Company; the Santa Clara park operates today as California's Great America. In the years after their sale, the layouts of the parks have diverged substantially.