The Nguni languages are a group of Bantu languages spoken in southern Africa (mainly South Africa, Zimbabwe and Eswatini) by the Nguni people. Nguni languages include Xhosa, Ndebele, Swati, and Zulu. The appellation "Nguni" derives from their ancestor called Mnguni type. Ngoni (see below) is an older, or a shifted, variant.

It is sometimes argued that the use of Nguni as a generic label suggests a historical monolithic unity of the people in question, where in fact the situation may have been more complex. The linguistic use of the label (referring to a subgrouping of Bantu) is relatively stable.

From an English editorial perspective, the articles "a" and "an" are both used with "Nguni", but "a Nguni" is more frequent and more correct especially if "Nguni" is pronounced as it is suggested (/ŋˈɡuːni/)^{[by whom?]}.

Within a subset of Southern Bantu, the label "Nguni" is used both genetically (in the linguistic sense) and typologically (quite apart from any historical significance).

The Nguni languages are closely related, and in many instances different languages are mutually intelligible; in this way, Nguni languages might better be construed as a dialect continuum than as a cluster of separate languages. On more than one occasion, proposals have been put forward to create a unified standard Nguni language.

In scholarly literature on southern African languages, the linguistic classificatory category "Nguni" is traditionally considered to subsume two subgroups: "Zunda Nguni" and "Tekela Nguni". This division is based principally on the salient phonological distinction between corresponding coronal consonants: Zunda /z/ and Tekela /t/ (thus the native form of the name Swati and the better-known Zulu form Swazi), but there is a host of additional linguistic variables that enables a relatively straightforward division into these two substreams of Nguni.

Note: Maho (2009) also lists S401 Old Mfengu^†.

The following aspects of Nguni languages are typical: