LaGuardia Airport opened for commercial traffic on December 2, 1939, when a TWA DC-3 from Chicago landed just after midnight, the first scheduled flight at New York City's own airport. Built with backing from the New Deal's Works Progress Administration, it opened as New York Municipal Airport-LaGuardia Field after a $40 million overhaul of what had previously been a private airfield on land once occupied by an amusement park run by the Steinway family. Within a year it was the busiest airport in the world.

Situated in East Elmhurst, Queens, roughly 8 miles from Midtown Manhattan, LGA is the closest of the three major New York area airports to the city center. That proximity made it the preferred airport for business travelers for decades. It has always been a domestic-focused hub: since 1984, a perimeter rule has restricted most nonstop flights to destinations within 1,500 miles, channeling long-haul and international traffic to JFK. Delta Air Lines and American Airlines are the 2 largest carriers, operating from separate terminal complexes. The airport logged more than 32 million passengers in 2023.

The original Marine Air Terminal, built in 1939 and designed in the Art Deco style by Delano & Aldrich, survives as Terminal A and houses a WPA mural called Flight completed by James Brooks in 1942. The rest of the airport is unrecognizable from its mid-20th-century form. An $8 billion reconstruction launched in 2016 replaced the aging Central Terminal Building with a new 1.3-million-square-foot Terminal B, completed in phases between 2018 and 2022. The project made LGA the first airport in the world with dual pedestrian skybridges spanning active taxiways. The full airport transformation, including Delta's new Terminal C, was completed by the end of 2024.