The Antares Quadrant lies in the Epsilon Sector and consists of the Antares, Bistangio, Charon, Circe, Corsair, D'vd Tang, Firekka, Granita, K'k-Tahn, K'ta Mek, Khar Takh, Khar-Sa, Midgard, N'Tanya, S'thran-Pak, Shariha, T'kirsa, Trafalgar, Tv'x Aq, and Veronica systems.
The Antares Quadrant saw extensive action during the Terran-Kilrathi War. From 2655 to 2656, the Terran Confederation fought the Kilrathi Empire when the later invaded Firekka. The siege eventually ended in a Terran-Firekkan victory, and it severely weakened the Kilrathi's claim on the quadrant. During this campaign the Terrans, led by the TCS Tiger's Claw fought off the invaders at Charon before being forced to retreat, inflicting heavy losses on the Kilrathi and ensuring victory on Firekka.
Since the failure of the Firekka invasion, the Kilrathi planets of Shariha and N'Tanya have seceded from the Empire and joined the Terrans. In 2669, Trafalgar was wiped out with biological weapons, and Bistangio was left in ruins in a surprise attack. Facing near-defeat, the Terran colony at Granita attempted to broker peace with the Kilrathi, an effort eventually rendered moot by the Confederation's victory that same year. After the war ended, Circe saw itself in the midst of a brutal civil war in 2673. The devastated Trafalgar System repopulated, its citizens primarily stationed in deep space outposts. Finally, in 2678, the Firekkan Planetary Alliance was formed, and now consists of both Firekka and T'kirsa.
In the Wing Commander I video game, the Antares Quadrant is erroneously referred to as the "Antares Sector" in the ending scene of "Secret Missions II".