On April 8, 2016 stockholders of both Marriott International and Starwood Hotels & Resorts Worldwide approved the merger. On September 23, 2016, the merger closed with the Federal Trade Commission prior to market opening.

Yes, Starwood Hotels & Resorts officially became part of Marriott International following a landmark acquisition that closed on September 23, 2016. The $13.6 billion merger created the largest hotel company in the world at the time, bringing iconic Starwood brands like Westin, Sheraton, W Hotels, St. Regis, and Aloft under the Marriott umbrella. One of the most significant changes for travelers was the eventual consolidation of the "Starwood Preferred Guest" (SPG) program with "Marriott Rewards" and "The Ritz-Carlton Rewards" to create the unified Marriott Bonvoy loyalty program in 2019. In 2026, while the individual brand identities of the former Starwood properties have been carefully preserved to maintain their unique market positions, all back-end operations, booking systems, and elite benefits are fully integrated into the Marriott ecosystem. This merger allowed Marriott to significantly expand its global footprint, particularly in luxury and lifestyle segments where Starwood had historically held a very strong and loyal following among younger, design-conscious travelers.