Antipredator adaptations are evolutionary adaptations developed over time, which assist prey organisms in their constant struggle against their predators.

The act of a predator acquiring a food source can be divided into four stages: detection, attack, capture and consumption. At every stage in this predatory sequence, adaptations that maximize the prey's chance of survival have evolved. This, in turn, has driven adaptation in their predators. This kind of interaction over long periods is known as co-evolution.

Many predatory animals are themselves preyed upon. To defend themselves, predatory animals often use their methods of attacking prey to inflict or threaten grievous injury to their own predators. For example, the electric eel uses the same electrical currents to kill prey, and to defend itself against predators (such as anacondas, caimans, jaguars, egrets, cougars) which prey on fish of similar size to the eels.