Robert Moses (December 18, 1888 - July 29, 1981) was a public official who worked mainly in the New York metropolitan area. Known as the "master builder" of mid-20th century New York City, Long Island, Rockland County, and Westchester County, he is sometimes compared to Baron Haussmann of Second Empire Paris, and was one of the most polarizing figures in the history of urban development in the United States. His decisions favoring highways over public transit helped create the modern suburbs of Long Island and influenced a generation of engineers, architects, and urban planners who spread his philosophies across the nation despite not training in those professions. Moses would call himself a "coordinator" and was referred to in the media as a "master builder".

Robert Moses simultaneously held twelve titles (including NYC Parks Commissioner and Chairman of the Long Island State Park Commission), but was never elected to any public office. He created and led numerous public authorities that gave him autonomy from the general public and elected officials. Through these authorities, he controlled millions of dollars in income from his projects, such as tolls, and he could issue bonds to borrow vast sums for new ventures with little or no input from legislative bodies, allowing him to circumvent the power of the purse as it normally functioned in the United States, and the process of public comment on major public works. As a result of Moses' work, New York has the United States' greatest proportion of public benefit corporations, which are the prime mode of infrastructure building and maintenance in New York and account for most of the state's debt.

Moses' projects were considered by many to be necessary for the region's development after the Great Depression. During the height of his powers, New York City built campuses to host two World's Fairs: one in 1939 and the other in 1964. Moses also helped persuade the United Nations to locate its headquarters in Manhattan, instead of Philadelphia, by helping the state secure the money and land needed for the project.