["Journal of Child Psychology and Psychiatry, EarlyView. ", "\n\nBackground\nSensory over‐responsivity (SOR) is highly prevalent and impairing in autism spectrum disorder (ASD). SOR has been associated with sensory‐limbic hyperresponsivity and reduced prefrontal top‐down regulation during sensory stimulation. There are few evidence‐based treatments for SOR, but cognitive reappraisal, an emotion regulation strategy, has been shown to reduce negative feelings through activation of frontal brain regions. The current study examined whether reappraisal changes neural reactivity to aversive sensory stimulation in autistic compared to typically developing (TD) children.\n\n\nMethods\nForty‐seven ASD and 45 age/IQ‐matched TD youth aged 8–15 years participated in fMRI while experiencing aversive tactile stimulation on their arm and alternately focused either on how the stimulus made them feel (‘React’), or how they would describe the stimuli objectively (‘Reappraise’). Aversiveness ratings were provided after each stimulus. Parents reported on participants' SOR severity.\n\n\nResults\nAutistic youth showed reduced activation in sensory cortical regions during Reappraisal compared to React. Reappraisal also resulted in increased dorsomedial prefrontal cortex activation, with a trend toward more increases in the TD group but no significant group differences. Despite these reappraisal‐related neural changes across both groups, only TD youth showed a reduction in aversiveness ratings for Reappraisal compared to React. Among ASD youth, higher SOR was associated with fewer decreases in sensory cortices but greater increases in frontal regions during Reappraisal compared to React. Older ASD youth also showed increased activity in the ventral prefrontal cortex during Reappraisal.\n\n\nConclusions\nResults suggest that cognitive reappraisal modulates neural responses during sensory processing and, more specifically, may reduce hyperactivity in sensory cortical regions previously shown to be associated with SOR. However, individual differences such as age and SOR severity may affect the extent to which top‐down cognitive processes are uniquely engaged during reappraisal.\n\n"]