Asperger syndrome (AS), also known as Asperger's syndrome or Asperger disorder, is an autism spectrum disorder (ASD) characterized by significant difficulties in social interaction and restricted and repetitive patterns of behavior and interests.  Individuals with Asperger's syndrome typically have normal to superior intelligence.  Many have excellent rote memory and become intensely interested in one or two subjects.  This circumscribed area of interest may not leave room for more age appropriate, common interests.  Some examples are cars, trains, planes, maps, door knobs and hinges, washing machines, meteorology, astronomy or history.

Most children improve as they mature to adulthood, but social and communication difficulties may persist.   Some researchers and people with Asperger's have advocated a shift in attitudes toward the view that it is a difference, rather than a disability that must be treated or cured.

The name "Asperger" comes from Hans Asperger, an Austrian physician who first described the syndrome in 1944.