Newark Liberty International Airport opened on October 1, 1928, built on 68 acres of reclaimed marshland adjacent to Port Newark. It was the first major airport in the New York metropolitan area and rapidly became the busiest commercial airport in the world. The airport held a string of firsts: it was the first in the United States, and reputedly the world, to have a paved runway, and its Art Deco administration building, dedicated by Amelia Earhart in 1935, was the first passenger terminal in the United States. During World War II, the Army Air Corps took over the facility; commercial operations did not resume until 1946. The Port Authority of New York and New Jersey assumed control in 1948.

Situated approximately 9 miles west-southwest of Midtown Manhattan, EWR is the second-busiest airport in the New York airport system, behind John F. Kennedy International. It serves as a major gateway to Europe, South America, the Caribbean, and Asia. United Airlines is the dominant carrier, accounting for roughly 63% of passengers and occupying Terminal C exclusively for its mainline and international operations. FedEx Express is the airport's second-largest tenant. The airport handled a record 49.1 million passengers in 2023.

The three-terminal layout (A, B, and C) spans the boundary between Newark and Elizabeth, New Jersey. A $2.7 billion Terminal A, designed by Grimshaw Architects, opened in January 2023 as the largest design-build infrastructure project in New Jersey's history, replacing the original 1973 structure. The terminals are connected by AirTrain Newark, a monorail people-mover that opened on May 31, 1996, and also links the airport to Amtrak and NJ Transit rail service on the Northeast Corridor. The airport was renamed Newark Liberty International in 2002, honoring the victims of Flight 93, which departed EWR on September 11, 2001.