State Department spokesman John Kirby announced the release in a statement without identifying the individual.
The Washington Post, citing two US officials, reported earlier Friday that Syria's government had released Kevin Dawes, who was abducted after traveling to the civil war-ravaged nation in 2012.
Dawes, described by the newspaper as a freelance photographer, was recently allowed to call family and receive care packages, signaling to officials that the Syrian government was moving toward his release, the Post reported.
The newspaper said Dawes' release was seen as a positive sign for American reporter Austin Tice, who also went missing in Syria in 2012.
The State Department is continuing to work through Czech officials in Syria to get information on Tice as well as on other US citizens missing in Syria.
Tice's family declined to comment.