Agoraphobia is a mental and behavioral disorder, specifically an anxiety disorder characterized by symptoms of anxiety in situations where the person perceives their environment to be unsafe with no easy way to escape. These situations can include open spaces, public transit, shopping centers, crowds and queues, or simply being outside their home on their own. Being in these situations may result in a panic attack. Those affected will go to great lengths to avoid these situations. In severe cases, people may become completely unable to leave their homes.

Agoraphobia is believed to be due to a combination of genetic and environmental factors. The condition often runs in families, and stressful or traumatic events such as the death of a parent or being attacked may be a trigger. In the DSM-5 agoraphobia is classified as a phobia along with specific phobias and social phobia. Other conditions that can produce similar symptoms include separation anxiety, post-traumatic stress disorder, and major depressive disorder. The diagnosis of agoraphobia has been shown to be comorbid with depression, substance abuse, and suicide ideation.

Without treatment it is uncommon for agoraphobia to resolve. Treatment is typically with a type of counselling called cognitive behavioral therapy (CBT). CBT results in resolution for about half of people. In some instances, those with a diagnosis of agoraphobia have reported taking benzodiazepines and antipsychotics augmentation. Agoraphobia affects about 1.7% of adults. Women are affected about twice as often as men. The condition is rare in children, often begins in early adulthood, and becomes less common in old age.