The first two batches were made public on May 8 and May 22.
President Donald Trump is the latest president to release US government reports on unidentified flying objects, a disclosure process that began in the late 1970s.
Friday's release of what the Pentagon calls "unidentified anomalous phenomena" (UAP) involved 72 files from the FBI, CIA and Pentagon and includes testimony, videos and artistic depictions.
Reports from several entries refer to sphere or orb sightings in the same general northeast US location.
One file from February 2026 cites FBI interviews with two people who reported seeing an intense bright light in the middle of their backyard one evening.
The identities of those interviewed and their precise location were blacked out.
One person "described the red colour as being brilliant and beautiful, and that (redacted) had never seen anything that colour of red before," according to the FBI report.
The red sphere, about one metre wide, contained a "white plasma sun" the size of a basketball in its centre, it said.
The people noticed a second orb and the two appeared tethered together as they moved away.
They reported seeing several white orbs a few weeks later flying over the house at a much higher altitude, the FBI report said.
A similar interview in July 2025 referred to previous reports of orbs.
"This observation occurred within 25 miles of the 'Triangle Orbs,' 'Red Orb Rotation,' and 'Orbs Over the Pond,' sightings at a location well known to them, which is sparsely populated," the FBI report said.
An October 2024 incident describes a light source below the horizon, hovering above a pond.
"The luminous object resembled a 'plasma-like sphere' intermittently changing shape and luminosity. At times, the primary light source appeared to separate into smaller luminous points," according to the report.
"These files, hidden behind classifications, have long fuelled speculation - and it's time the American people see it for themselves," Pentagon chief Pete Hegseth said in a statement.
