Historically, individuals with intellectual disability (ID) have been excluded from pain research and assumed to be insensitive or indifferent to pain. The weight of the evidence suggests that individuals with ID have been subject to practices and procedures with little regard for their ability to experience or express pain. A number of issues central to improving understanding of pain in ID will be introduced and current research related to the definition of pain and its social context, underlying sensory and metabolic systems and factors influencing judgments about the ability to experience pain will be reviewed. Accumulating evidence from interdisciplinary research designed to improve assessment, understand individual differences, and evaluate bias and beliefs about pain suggests that new perspectives are emerging and beginning to shape an innovative frontier of research that will ultimately pay tremendous dividends for improving the quality of life of individuals with ID.