The Ngumbur language is an Australian

Australian Aboriginal languages

The Australian Aboriginal languages comprise several language families and isolates native to the Australian Aborigines of Australia and a few nearby islands, but by convention excluding the languages of Tasmania and the Torres Strait Islanders...

 language isolate

Language isolate

A language isolate, in the absolute sense, is a natural language with no demonstrable genealogical relationship with other languages; that is, one that has not been demonstrated to descend from an ancestor common with any other language. They are in effect language families consisting of a single...

 spoken by just one person in Arnhem Land

Arnhem Land

The Arnhem Land Region is one of the five regions of the Northern Territory of Australia. It is located in the north-eastern corner of the territory and is around 500 km from the territory capital Darwin. The region has an area of 97,000 km² which also covers the area of Kakadu National...

, northern Australia, as of 1981. By 2009 Ethnologue reported that it was extinct.

Ngumbur is not known to be related to any other language. It has been suggested that it may be related to the Umbugarla

Umbugarla language

The Umbugarla language is an Australian language isolate spoken by just three people in Arnhem Land, northern Australia, as of 1981. It may now be extinct....

 isolate, forming a Umbugarla–Ngurmbur language family

Language family

A language family is a group of languages related through descent from a common ancestor, called the proto-language of that family. The term 'family' comes from the tree model of language origination in historical linguistics, which makes use of a metaphor comparing languages to people in a...

, but it has also been tentatively included in a proposed Macro-Pama–Nyungan family.