The black and white videos were recorded by Navy pilots - one in November 2004 and two in January 2015, the US Department of Defense said.
The footage had been shared online unofficially and was well known to UFO enthusiasts but the Pentagon said on Monday that it had chosen to release the videos officially.
One of the clips shows a dark circular object flying in front of a jet, another shows a small object speeding over land and the third shows a circular object racing and then appearing to slow down as it approaches the camera.
One of the videos was filmed over the Pacific and the other two were on the US east coast, according to reports.
Another voice adds: "They're all going against the wind. The wind's 120 knots to the west. Look at that thing, dude!"
The US Department of Defense said in a statement: "DOD is releasing the videos in order to clear up any misconceptions by the public on whether or not the footage that has been circulating was real, or whether or not there is more to the videos."
They added that the videos had been reviewed to determine that they did not reveal any "sensitive capabilities or systems" or "impinge on any subsequent investigations of military air space incursions by unidentified aerial phenomena".
