尼日尔尔-刚果语系分布在非洲的中部和非洲南部部分地区。大部分尼日尔尔-刚果语系语言都是声调语言，词句顺序通常为主谓宾结构（SVO）。而南非的祖鲁语和科萨语，受到邻近的科依桑语系语言影响，而带有搭嘴音（吸气音）。

斯瓦希里语为此语系使用人数最多的语言，其位于坦桑尼亚东部和肯尼亚东南部。采用斯瓦希里语的母语用户约5百万，计算第二语言用户则多达5千万人。其次为津巴布韦的绍纳语（Shona）和南非的祖鲁语，均各有约1千万用户。

The Niger–Congo languages constitute one of the world's major language families, and Africa's largest in terms of geographical area, number of speakers, and number of distinct languages. They may constitute the world's largest language family in terms of distinct languages, although this question is complicated by ambiguity about what constitutes a distinct language.