Escape response, escape reaction, or escape behavior is a mechanism by which animals avoid potential predation. It consists of a rapid sequence of movements, or lack of movement, that position the animal in such a way that allows it to hide, freeze, or flee from the supposed predator. Often, an animal's escape response is representative of an instinctual defensive mechanism, though there is evidence that these escape responses may be learned or influenced by experience.

The classical escape response follows this generalized, conceptual timeline: threat detection, escape initiation, escape execution, and escape termination or conclusion. Threat detection notifies an animal to a potential predator or otherwise dangerous stimulus, which provokes escape initiation, through neural reflexes or more coordinated cognitive processes. Escape execution refers to the movement or series of movements that will hide the animal from the threat or will allow for the animal to flee. Once the animal has effectively avoided the predator or threat, the escape response is terminated. Upon completion of the escape behavior or response, the animal may integrate the experience with its memory, allowing it to learn and adapt its escape response.

Escape responses are anti-predator behaviour that can vary from species to species. The behaviors themselves differ depending upon the species, but may include camouflaging techniques, freezing, or some form of fleeing (jumping, flying, withdrawal, etc.). In fact, variation between individuals is linked to increased survival. In addition, it is not merely increased speed that contributes to the success of the escape response; other factors, including reaction time and the individual's context can play a role. The individual escape response of a particular animal can vary based on an animal's previous experiences and its current state.

The ability to perform an effective escape maneuver directly affects the fitness of the animal, because the ability to evade predation enhances an animal's chance of survival. Those animals that learn to or are simply able to avoid predators have contributed to the wide variety of escape responses seen today. Animals that are able to adapt their responses in ways different from their own species have displayed increased rates of survival. Because of this, it is common for the individual escape response of an animal to vary according to reaction time, environmental conditions, and/or past and present experience.

Arjun Nair et al. found in 2017 that it is not necessarily the speed of the response itself, but the greater distance between the targeted individual and the predator when the response is executed. In addition, the escape response of an individual is directly related to the threat of the predator. Predators that pose the biggest risk to the population will evoke the greatest escape response. Therefore, it may be an adaptive trait selected for by natural selection.

Law and Blake argued in 1996 that many morphological characteristics could contribute to an individual's efficient escape response, but the escape response has undoubtedly been molded by evolution. In their study, they compared more recent sticklebacks to their ancestral form, the Paxton Lake stickleback, and found that the performance of the ancestral form was significantly lower. Therefore, one may conclude that this response has been ripened by evolution.

How the escape responses are initiated neurologically, and how the movements are coordinated is dependent on the species. The behaviors alone vary widely, so, in a similar manner, the neurobiology of the response can be highly variable between species.

'Simple' escape responses are commonly reflex movements that will quickly move the animal away from the potential threat. These neural circuits operate quickly and effectively, rapidly taking in sensory stimuli and initiating the escape behavior through well-defined neuron systems.