Juan Acero was a Human Starfleet officer during the 24th century. (Star Trek: The Farthest Star)

By 2369, Acero had risen to the rank of captain and was serving as the commanding officer of the USS Proxima.

In the same year Acero led a delegation from the Proxima to attend a function to celebrate their first contact with the Iorathites on their homeworld. During the function he met the Vorta Jasis who kidnapped him to learn more about the United Federation of Planets.

Acero was drugged and interrogated by the Jasis on her ship. He revealed the location of the Federation as well as the existence of the Bajoran wormhole to the Vorta. He was later transferred to another Dominion vessel to be taken to a more appropriate location along with the recently captured crew of the Proxima. ("To Seek and to Be Found")