智力障碍（英语：Intellectual disability，缩写为 ID，或 general learning disability），又称智障，是指在一般的金钱管理、阅读识字、计算、日常生活等需要使用智力思考的行为之障碍。同义词还有心智迟缓（英文为：mental retardation，简称MR），是指资质、能力迟缓的表现，大多都为印象或比较下才可得到的结果。在美国像这样的障碍通常用「心智迟缓」（mental retardation）称呼，同时以这个领域为研究范围的相关国际学会，也使用「mental retardation」作为正式名称。

Intellectual disability (ID), also called intellectual developmental disability (IDD), general learning disability, or mental retardation (MR), is a generalized neurodevelopmental disorder characterized by significantly impaired intellectual and adaptive functioning. It is defined by an IQ score under 70 in addition to deficits in two or more adaptive behaviors that affect everyday, general living. Once focused almost entirely on cognition, the definition now includes both a component relating to mental functioning and one relating to individuals' functional skills in their environments. As a result of this focus on the person's abilities in practice, a person with an unusually low IQ may not be considered intellectually disabled. Intellectual disability is subdivided into syndromic intellectual disability, in which intellectual deficits associated with other medical and behavioral signs and symptoms are present, and non-syndromic intellectual disability, in which intellectual deficits appear without other abnormalities. Down syndrome and fragile X syndrome are examples of syndromic intellectual disabilities.