The Qax were an alien species from Stephen Baxter's Xeelee Sequence. They were lifeforms composed of convection cells, needing to live in turbulent substances. They subjugated humanity in the 51st century, farming the Earth for organic compounds and destroying human ships with their organic Spline Warships. The species was greatly weakened and traumatized when a human pilot forced the Qax to destroy their own sun with gravitation-wave "starbreaker" beams.