指小词缀，又称小称词缀，是一些语言中的一种屈折变化，主要接于名词或形容词，用来表示「小的」、「少的」之意思的词缀。大多数指小词缀为后缀，不过在汉语、日语也有「小-」这般的前缀。指小词缀在本义上添加了小尺寸、年轻、亲昵（暱称）、爱慕或轻视等附加含义。后缀时称为指小后缀（diminutive suffix）。

在汉语中，某些方言会有指小屈折，如北京话会加上儿化音，粤语及闽南语加上「仔」字，只外有些方言则加上「子」字。韩语也有指小屈折，多为「儿（아）」。拉丁语和俄语中，指小屈折比较发达。在德语中，指小屈折的应用受到了限制。在英语中，能添加指小后缀的只有少数词，因此可以认为英语的名词已经不存在指小屈折。

A diminutive is a word which has been modified to convey a slighter degree of its root meaning, to convey the smallness of the object or quality named, or to convey a sense of intimacy or endearment. A diminutive form (abbreviated DIM) is a grammatical inflection used to express such meanings; in many languages, such inflections can be translated as "little" and diminutives can also be formed as multi-word constructions such as "Tiny Tim". Diminutives are used frequently when speaking to small children or when expressing extreme tenderness and intimacy to an adult. As such, they are often employed for nicknames and pet names. The opposite of the diminutive form is the augmentative.