The Intrepid Museum (originally the Intrepid Sea, Air & Space Museum) is a military and maritime history museum in New York City, United States. It is located at Pier 86 at 46th Street, along the Hudson River, in the Hell's Kitchen neighborhood on the West Side of Manhattan. The museum is mostly composed of exhibits, aircraft, and spacecraft aboard the museum ship USS Intrepid, a World War II–era aircraft carrier and National Historic Landmark, in addition to a cruise missile submarine named USS Growler and a Concorde on Pier 86. The Intrepid Museum Foundation, a 501(c)(3) organization established in 1979, operates the museum.

The museum was proposed in the late 1970s as a way to preserve Intrepid, and it opened on August 3, 1982. The Intrepid Museum Foundation filed for bankruptcy protection in 1985 after struggling to attract visitors. The foundation acquired USS Growler and the destroyer USS Edson in the late 1980s to attract guests and raise money, although it remained unprofitable through the 1990s. The museum received a minor renovation in 1998 after it started turning a profit. Between 2006 and 2008, the Intrepid Museum was completely closed for a $115 million renovation. A new pavilion for the Space Shuttle Enterprise opened in 2012.

The Intrepid Museum spans three of the carrier's decks; from top to bottom, they are the flight, hangar, and gallery decks. Most of the museum's collection is composed of aircraft, many of which were used by the United States Armed Forces. Among the museum's collection are a Concorde SST, a Lockheed A-12 supersonic reconnaissance plane, and the Space Shuttle Enterprise. The hangar and gallery decks contain a variety of attractions such as exhibit halls, a theater, and flight simulators, as well as individual objects like a cockpit and an air turbine. Several craft and other objects have been sold off or removed from the museum's collection over the years. The museum serves as a space for community and national events, such as Fleet Week and awards ceremonies, in addition to educational programs.

USS Intrepid, an Essex-class aircraft carrier, was launched in 1943. She participated in World War II, the Korean War, and the Vietnam War, and was a recovery ship for space missions. Intrepid was supposed to be scrapped after decommissioning in the late 1970s, but Odysseys in Flight, a nonprofit organization founded by Michael D. Piccola and Bruce Sherer, wished to convert Intrepid into a museum ship. Odysseys in Flight had initially planned to salvage the carriers Lexington or Franklin D. Roosevelt. The United States Navy wanted the organization to raise $3 million for the carrier's upkeep. The organization hosted an exhibit at 6 World Trade Center to raise support for the project, and Odysseys in Flight had raised $2 million by March 1979. One of the museum's largest supporters was local real estate developer Zachary Fisher, who established the Intrepid Museum Foundation in March 1978 and contributed over $25 million to the museum during his lifetime. Fisher was enthusiastic about the project, eventually attracting other high-profile supporters such as radio and TV personality Arthur Godfrey and actress Maureen O'Hara. The Navy also hoped that Intrepid could be used for recruitment.

Mayor Ed Koch announced plans for the Intrepid's conversion in mid-April 1981, and the United States Department of the Navy transferred the Intrepid to Fisher, who led the nonprofit Intrepid Museum Foundation, on April 27, 1981. The conversion of the carrier's top two decks cost $22 million and was funded by $2.4 million in private donations, as well as $15.2 million of tax-exempt bonds and $4.5 million from the United States Department of Housing and Urban Development. After the New York City Board of Estimate gave the Intrepid Museum Foundation permission to sell tax-exempt bonds in December 1980, the bonds were sold to the public in July 1981. The federal grant was approved in January 1982, even though the project "had nothing to do with housing". The renovation involved the addition of a theater, several planes on Intrepid's deck, and aviation and maritime exhibit halls. The carrier's navigation and flight bridges were also restored. The city spent around $2.5 million to renovate Pier 86 on the West Side of Manhattan, where Intrepid was to be docked. The museum leased the pier from the city for 33 years at $50,000 per year, making annual payments in lieu of taxes totaling $400,000.

Intrepid was towed to her permanent home at Pier 86 in June 1982. Following a soft opening on July 4, the museum opened on August 3, 1982, as the Intrepid Sea, Air & Space Museum. This made Intrepid the second aircraft carrier in the U.S. to be converted into a museum, after the USS Yorktown. Larry Sawinski was named as the museum's director of exhibits. When the Intrepid Museum opened, it showcased several aircraft and spacecraft, and it also contained an exhibit on the early history of carriers. The exhibit halls on hangar level (including Pioneer Hall and Navy Hall), as well as the theater, were not completed. Maritime and aviation schools were planned for the lower two decks, the renovation of which was expected to cost $22 million. The museum had 50 paid staff, who worked mostly in the cafeteria, gift shop, and ticket booths; another 100 volunteers were responsible for the museum's displays and expansion. The museum's opening was expected to create 469 jobs in the surrounding area, though many of these jobs never materialized.

The Intrepid Museum Foundation dedicated the Hall of Honor, the United States' first archive dedicated to Medal of Honor recipients, on December 10, 1983; the Medal of Honor Society also relocated into offices within the carrier. The museum originally was projected to attract 1.3 to 1.4 million visitors annually, but it recorded only half of this amount in its first year. This forced the museum's directors to delay payments on its debt. The museum had recorded 450,000 patrons in 1984, nearly half of the 800,000 annual patrons that were required to break even. Attendance had been negatively impacted because of the lack of nearby public transit, and the museum struggled to raise money despite increasing its ticket prices. Nonetheless, the museum planned to expand by 1984; it had received $250,000 from the Astor Foundation for classrooms and conference rooms, and the New York state government gave $850,000 for historic preservation. Film and television executive Stanley Abrams was named as the museum's president in June 1984.

The Intrepid Museum Foundation filed for Chapter 11 bankruptcy protection in 1985, declaring $28.4 million in debt and $16.5 million in assets. Only about a third of the museum's revenues came from admissions, with the remaining two-thirds coming from grants, donations, or fundraisers and other such events. Nonetheless, museum officials planned to continue normal operations and launch a campaign to attract visitors; Lawrence Sowinski, the director of exhibits, described the museum as "too valuable a resource to close". Advertising firm McCann-Erickson was hired to promote the museum, running cheap advertisements in newspapers, on the radio, and in New York City Subway cars. The state also provided $1.024 million for the museum in its 1985 budget, though ultimately the museum got $850,000. Intrepid was officially designated as a National Historic Landmark in 1986, and its annual allocation from the state was raised to $895,000 that year. Investigators announced in early 1987 that members of the Westies gang had engaged in racketeering, stealing $100,000 to $120,000 annually from the Intrepid Museum.