New Hampshire is a New England state bordered by Massachusetts, Vermont, Maine and the Canadian province of Quebec, with the White Mountains across its north and an Atlantic coastline of only about 18 miles. Its seacoast was home to Pease Air Force Base in Portsmouth, a Strategic Air Command bomber base from 1956 until 1991, which figures in both of the state's best-known UFO cases.

The first is the Betty and Barney Hill abduction. Driving home to Portsmouth on U.S. Route 3 through the White Mountains on the night of September 19–20, 1961, the couple saw a light they came to believe was a craft, and on a police chief's advice Betty Hill reported it to Pease. Under hypnosis with the Boston psychiatrist Benjamin Simon they later described being taken aboard and examined, although Simon concluded the case was a "singular psychological aberration." John G. Fuller's 1966 book The Interrupted Journey and NBC's 1975 film The UFO Incident made the account famous. Most of Betty Hill's papers are held by the University of New Hampshire, and in 2011 the state's Division of Historical Resources placed a historical marker commemorating the encounter.

The second began at about 2 a.m. on September 3, 1965, when Norman Muscarello, an 18-year-old hitchhiker, told police in Exeter that a silent object with flashing red lights had hovered over a field in neighboring Kensington. Officers Eugene Bertrand and David Hunt then said they saw it too. An Air Force investigator noted five Pease B-47s flying in the area but judged them unconnected. The Pentagon first attributed the sighting to stars, planets and a temperature inversion, and Project Blue Book later pointed to a training exercise, Operation Big Blast, which the officers said had ended nearly an hour earlier; in January 1966 the Air Force wrote to them that it had been "unable to identify the object." Fuller's 1966 bestseller Incident at Exeter carried the case nationally, and in 2011 Joe Nickell and James McGaha proposed in Skeptical Inquirer that the lights came from a KC-97 refueling tanker.

Both cases are still marked each year. The Exeter Area Kiwanis Club sponsors the annual Exeter UFO Festival on Labor Day weekend, and its 2026 edition on September 5–6 featured the Hills' niece Kathleen Marden speaking about her aunt and uncle's account. New Hampshire's place in UFO history rests on those two 1960s cases: the first widely publicized American abduction narrative, and a police sighting that the Air Force conceded it could not identify.