Sensory processing disorder (SPD) is a condition in which multisensory input is not adequately processed in order to provide appropriate responses to the demands of the environment. Sensory processing disorder is present in many, but not all people with autism spectrum disorders.

Sensory processing disorder was formerly known as sensory integration dysfunction.

Sensory integration was defined by occupational therapist Anna Jean Ayres in 1972 as "the neurological process that organizes sensation from one's own body and from the environment and makes it possible to use the body effectively within the environment". Sensory processing disorder has been characterized as the source of significant problems in organizing sensation coming from the body and the environment and is manifested by difficulties in the performance in one or more of the main areas of life: productivity, leisure and play or activities of daily living.

Sources debate whether SPD is an independent disorder or represents the observed symptoms of various other, more well-established, disorders. SPD is not included in the Diagnostic and Statistical Manual of the American Psychiatric Association, and the American Academy of Pediatrics has recommended that pediatricians not use SPD as a stand-alone diagnosis.