The Antares Ship Yards was a Federation shipyard located in the Bajor sector.
The Defiant-class prototype USS Defiant was launched from the Antares yards in 2370, on stardate 47538.5. (DS9: "The Search, Part I", dedication plaque) The USS Valiant was launched from there in 2372, on stardate 49456.5. (DS9: "Valiant", dedication plaque)
In the mirror universe, the Antares Ship Yards was a Terran Empire shipyard in the 22nd century. The ISS Avenger was constructed at these yards. (ENT: "In a Mirror, Darkly, Part II" dedication plaque)
According to Star Trek: The Next Generation Technical Manual (p. 4), the USS Enterprise-B was launched from the Antares Ship Yards, however in Star Trek Generations we saw the ship launched for her maiden voyage from the spacedock NAR-30974, located in Earth orbit.