| ~Sep 2023 | Possible meteor or UAP observed near restricted range — September 2023 Restricted military range, United States (location redacted) | FBI | unknown | — | Unresolved | |
| ~Sep 2023 | Cigar-shaped metallic object observed near restricted military gate — September 2023 Restricted military installation, United States (location redacted) | FBI | cylinder | hover | Unresolved | |
| ~Sep 2023 | Cigar-shaped UAP sighting corroborated by second witness — September 2023 Restricted military installation, United States (location redacted) | FBI | cylinder | — | Unresolved | |
| ~Jul 1966 | FBI monitoring of Amalgamated Flying Saucer Clubs of America (AFSCA) publications — 1966 Los Angeles, California | FBI | — | — | Unknown | |
| ~Mar 1966 | UFOs tracked by radar over wide section of Washington, D.C. area — March 1966 Washington, D.C. area | FBI | unknown | — | Unknown | |
| Apr 24, 1964 | Officer Lonnie Zamora egg-shaped craft with humanoid figures — Socorro, New Mexico, April 1964 Socorro, New Mexico (approximately 1 mile southwest of Socorro) | FBI | ellipsoid | responsive | Unknown | |
| Feb 25, 1959 | Three bright objects accompanying airliner — Pennsylvania to Ohio, February 25, 1959 Phillipsburg, Pennsylvania to Cleveland, Ohio (airborne) | FBI | orb | interactive | Unresolved | |
| Nov 17, 1958 | William Rhodes Phoenix disc photographs follow-up — Arizona Republic inquiry, November 1958 Phoenix, Arizona | FBI | disc | — | Unknown | |
| Oct 13, 1958 | FBI policy memorandum on unidentified flying objects — October 1958 Washington, D.C. | FBI | — | — | Unknown | |
| Apr 17, 1958 | Circular object with crystal dome — Detroit, Michigan, April 17, 1958 Detroit, Michigan — 3 blocks south of Six Mile Road at Lamphere Street | FBI | disc | transit | Unresolved | |
| Nov 11, 1957 | Hat-shaped flying disc over Matahambre, Cuba — November 1957 Matahambre, Pinar del Rio Province, Cuba | FBI | disc | hover | Unknown | |
| ~Nov 1957 | Cigar-shaped object causing car engine failures — West Texas, November 1957 West Texas (approximate, multiple roadway reports) | FBI | cylinder | hover | Unresolved | |
| ~Oct 1957 | Post-Sputnik UFO wave — multiple U.S. reports summarized by FBI — October–November 1957 Multiple U.S. locations | FBI | unknown | — | Explained | |
| Jul 30, 1956 | Multiple 'flying saucer' sightings with police confirmation — Saginaw, Michigan, July 30, 1956 Saginaw, Michigan area | FBI | disc | transit | Unresolved | |
| Sep 21, 1954 | Air Force Intel Officer confirms flying saucers 'do exist' — Cincinnati civilian researcher interview Wright-Patterson Air Force Base, Dayton, Ohio | FBI | — | — | Unknown | |
| Sep 21, 1954 | CRIFO — Col. O'Mara confirms flying saucers exist — Cincinnati newsletter (Section 8 detail) Wright-Patterson Air Force Base, Dayton, Ohio | FBI | — | — | Unknown | |
| Sep 18, 1954 | Cigar-shaped object over Rome, Italy — September 1954 Rome, Italy | FBI | cylinder | hover | Unknown | |
| Sep 5, 1954 | Luminous object ascending from lunar surface — Rockford, Illinois, telescope observation, September 1954 Rockford, Illinois | FBI | orb | maneuver | Unknown | |
| Jul 23, 1954 | Silver circular object observed by civilians near Milford, Ohio — July 1954 Milford, Ohio (approximately 2 miles east on U.S. Highway 28) | FBI | disc, ellipsoid | — | Unknown | |
| Jul 23, 1954 | Silver circular object observed by civilians near Milford, Ohio — July 1954 (Section 8 detail) Milford, Ohio (approximately 2 miles east on U.S. Highway 28) | FBI | disc, ellipsoid | — | Unknown | |
| ~Jul 1954 | Mrs. Swan — thought-transmission contact with 'outer space' — Navy/FBI interest South Berwick, Maine | FBI | — | — | Unknown | |
| ~Jul 1954 | Mrs. Frances Swan — thought-transmission contact with 'outer space' — Navy/FBI interest (Section 8 detail) South Berwick, Maine | FBI | — | — | Unknown | |
| ~Jun 1954 | Truman Bethurum — Nevada desert flying saucer contact claim — FBI inquiry Nevada desert | FBI | disc | — | Unknown | |
| ~Jun 1954 | Truman Bethurum — Nevada desert flying saucer contact claim — FBI inquiry (Cincinnati detail) Nevada desert | FBI | disc | — | Unknown | |
| Sep 19, 1952 | Strange white object streaking across Montana sky — September 1952 Montana (statewide reports, reported 100-mile streak) | FBI | unknown | transit | Unknown | |
| Aug 8, 1952 | Blue-and-orange saucer observed over Savannah River Plant, AEC Four Hundred Area, Savannah River Plant, South Carolina | FBI | disc | transit | Unknown | |
| ~Aug 1952 | Tinfoil-like debris and burned clover found in pasture — Jackson, Minnesota Jackson, Minnesota (rural pasture) | FBI | — | maneuver | Unknown | |
| ~Aug 1952 | Scoutmaster Desvergers encounter — West Palm Beach, Florida: burned cap examined by FBI lab West Palm Beach, Florida (desolate area) | FBI | disc | interactive | Unknown | |
| ~Aug 1952 | Anonymous German-language letter describing disc-shaped V-weapon — Cincinnati, 1952 | FBI | disc | — | Unknown | |
| Jul 31, 1952 | Unidentified aerial object photographed near Passaic, New Jersey — July 1952 Passaic, New Jersey | FBI | unknown | — | Unknown | |
| ~1952 | Albert K. Bender 'silenced' by three men — Bridgeport, Connecticut, 1952 Bridgeport, Connecticut | FBI | — | — | Unknown | |
| ~Jan 1950 | Crashed flying saucers reportedly held at US radar station — secondhand hearsay New Mexico-Arizona border area (reported location) | FBI | disc | — | Unknown | |
| ~1950 | Horacio Robles Jr. disc photographs — Durango, Mexico, circa 1950 Durango, Mexico | FBI | disc | — | Unknown | |
| Sep 25, 1949 | Rocket-like object observed from aircraft near Parkersburg, West Virginia Lubeck, near South Parkersburg, West Virginia | FBI | cylinder | transit | Unknown | |
| ~Aug 1949 | Flying disc reports near Camp Hood, Texas — multiple sightings Camp Hood, Texas | FBI | disc | — | Unknown | |
| ~Jul 1, 1949 | Flying saucer sighted near Lake of the Woods, Canada — OSI-FBI coordination Lake of the Woods, Canada | FBI | disc | — | Unknown | |
| ~Dec 1948 | Experimental kite identified as 'flying disk' — Helendale, California, December 1948 Helendale, California (private airport in Mojave Desert) | FBI | disc | — | Explained | |
| Oct 16, 1948 | Football-shaped object with throbbing sound — Sterling, Utah, October 16, 1948 1 mile SE of Sterling, Utah | FBI | football | transit | Unresolved | |
| ~Oct 1948 | L. E. Gorman aerial dogfight with luminous object — Fargo, North Dakota, October 1948 Fargo, North Dakota | FBI | orb | responsive | Unknown | |
| Mar 13, 1948 | High-altitude fast-moving white streak heading east to west — Benkelman, Nebraska, March 13, 1948 Benkelman, Nebraska | FBI | cylinder | transit | Unresolved | |
| Oct 18, 1947 | Flying wing object heading NW toward Nome — Bethel, Alaska, October 18, 1947 (detail account) Bethel, Alaska | FBI | irregular | transit | Unresolved | |
| Sep 11, 1947 | Silver round/egg-shaped object at high speed — Portland, Oregon, September 11, 1947 Portland, Oregon | FBI | ellipsoid | maneuver | Unresolved | |
| Sep 11, 1947 | Silver elliptical object at high speed — Portland, Oregon, September 11, 1947 (police officer detail) Portland, Oregon | FBI | ellipsoid | maneuver | Unresolved | |
| Aug 13, 1947 | Sky-blue object with flame effect at ~1,000 mph — Twin Falls, Idaho, August 13, 1947 Salmon River canyon near Twin Falls, Idaho | FBI | irregular | transit | Unresolved | |
| Aug 4, 1947 | Pan Am Captain Alpheus Powell — orange cylinder sighting near Boston — August 1947 Near Boston, Massachusetts (Gander to LaGuardia route) | FBI | cylinder | transit | Unknown | |
| Aug 3, 1947 | Round black object moving north — Hackensack, New Jersey, August 3, 1947 Hackensack, New Jersey | FBI | disc | transit | Unresolved | |
| ~Aug 1947 | Flying wing object heading NW toward Nome — Bethel, Alaska, August 1947 Bethel, Alaska | FBI | irregular | transit | Unresolved | |
| ~Aug 1947 | Silver top-shaped object encountered by hiker — California mountains Mountains near Los Angeles, California | FBI | disc | responsive | Unresolved | |
| Jul 31, 1947 | Maury Island 'flying disc' fragments and B-25 crash — Maury Island, Washington, July 1947 (HOAX) Maury Island, Washington (Tacoma area) | FBI | disc | maneuver | Explained | |
| Jul 31, 1947 | Maury Island hoax investigation — Tacoma, Washington, July-August 1947 (detailed investigation file) Maury Island, Washington (investigation centered at Tacoma, WA) | FBI | disc | maneuver | Explained | |
| Jul 11, 1947 | Codroy, Newfoundland — flame-colored cone-shaped object — July 1947 Codroy (Cordroy), Newfoundland, Canada | FBI | unknown | transit | Unknown | |
| Jul 10, 1947 | Harmon Field, Newfoundland — C-54-sized circular disc with Kodachrome photographs — July 1947 Harmon Field, Newfoundland, Canada | FBI | disc | transit | Unknown | |
| Jul 9, 1947 | White light from ground with fused sand and trace radioactivity — Midland, Michigan, July 9, 1947 Midland, Michigan (Dow Chemical area) | FBI | orb | hover | Explained | |
| Jul 6, 1947 | Birmingham, Alabama mass sightings — hundreds of observers, round discs at high speed — July 1947 Birmingham, Alabama | FBI | disc | transit | Unknown | |
| Jul 5, 1947 | Approximately 12 flying discs — Darlington, South Carolina, July 5, 1947 Darlington, South Carolina | FBI | disc | — | Unresolved | |
| ~Jul 1947 | Circular disc identified as saw blade — Grafton, Wisconsin, ca. July 1947 Grafton, Wisconsin | FBI | disc | — | Explained | |
| ~Jul 1947 | Orange fireballs circling — Palestine, Texas, July 1947 Palestine, Texas | FBI | orb | maneuver | Unresolved | |
| ~Jul 1947 | Flying saucer covering 25 miles in 15 seconds — Southern Wisconsin, July-August 1947 Southern Wisconsin (airborne, two separate aircraft) | FBI | disc | maneuver | Unresolved | |
| ~Jul 1947 | William Rhodes disc photographs — Phoenix, Arizona, July 1947 Phoenix, Arizona | FBI | disc | maneuver | Unknown | |
| ~Jul 1947 | SS Burgeo marine saucer sightings — July 1947 (two incidents) Newfoundland coastal waters, Canada | FBI | disc | maneuver | Unknown | |
| ~Jul 1947 | Air Defense Command intelligence assessment — July 1947 disc observations summary Multiple locations, North America | FBI | disc | — | Unknown | |
| ~Jul 1947 | Flying saucer photographed at Oak Ridge, Tennessee — July 1947 Oak Ridge, Tennessee | FBI | unknown | — | Unknown | |
| Jun 30, 1947 | Grand Canyon, Arizona — F-80 pilot observes round objects at inconceivable speed — June 1947 Grand Canyon, Arizona | FBI | orb | transit | Unknown | |
| Jun 24, 1947 | Multiple round flying objects at ~6,000 mph — Mt. Adams, Oregon, June 24, 1947 Near Mt. Adams, Oregon (observer on ground with telescope) | FBI | disc | transit | Unresolved | |
| Jun 24, 1947 | F.H. Johnson — prospector corroborates Kenneth Arnold sighting near Mt. Adams — June 1947 Mt. Adams district, Washington State | FBI | disc | transit | Unknown | |
| Jun 23, 1947 | Dick Rankin — ten disc-shaped objects in formation over Bakersfield, California — June 1947 Bakersfield, California | FBI | disc | transit | Unknown | |
| Date unknown | WWII-era circular craft with rotating mid-section — Germany (KRASUSKI account), ca. 1939-1944 German-occupied territory (exact location not stated; observer was a POW work crew member) | FBI | disc | maneuver | Unknown | |
| Date unknown | FBI flying-saucer clippings & correspondence file (HQ 62-83894, Section 10) | FBI | — | — | Unknown | |