Gavan Breen (born 22 January 1935), OAM, also known as J.G. Breen, is an Australian linguist, specialising in the description of Australian Aboriginal languages. He has studied and recorded 49 such languages.
Breen was born at St Arnaud in the Wimmera district of the state of Victoria on 22 January 1935.  He received his secondary education at St Patrick's College, Ballarat (1948–1952), where he matriculated as Dux in his final year.  He went on to study at Newman College, graduating as a metallurgist from Melbourne University. 
He was thinking of somewhere to take a holiday break and a job when, in 1967, he chanced to listen to a public lecture at his university in which the need to record dying languages was mentioned. The work was well paid, and Breen took a grant to do a master's degree at Monash University, working initially with the last speakers of the Warluwarra language, and later with the Woorabinda people,  before deciding that this was where his vocation lay.   He was appointed a research fellow at Monash, and there worked on the Bidjara and sv:Gungabula languages and Pitta Pitta with Barry Blake. 
Breen's work, which has extended over many distinct language groups in western and central Queensland, the Northern Territory and South Australia, was mostly done under the auspices of the AIATSIS, of which he is now a member. He has studied and recorded 49 such languages.  Tasaku Tsunoda has suggested that, having worked with literally dozens of individuals who were the last speakers of a variety of Australian languages, Breen can be said to be the last speaker of the languages he has described, since he retains a working knowledge, if partial, of an otherwise extinct language. 
Although Breen officially retired in 2001, he continued to work at the Institute for Aboriginal Development in Alice Springs and was still there as of January 2016 [update] . He has also offered his expertise in legal cases, helping native peoples establish their claims to native title. 
On 26 January 2016, Breen was awarded the Officer of the Order of Australia. 
Languages Breen has helped to salvage include:
The Goreng Goreng, also known Kooreng Gooreng, are an inland Freshwater Australian Aboriginal people of Queensland, and also a language group. The Goreng Goreng area is between Central West Queensland in the north around Boyne Valley, extending westerly as far as the Great Dividing Range along the Dawes, Auburn, Nogo and Callide Ranges to meet the Wulli Wulli and Ghunghulu to their immediate west over the Great Dividing Range.
Yalarnnga is an extinct Australian Aboriginal language of the Pama–Nyungan language family, that may be related to the Kalkatungu language. It was formerly spoken by the Yalarnnga people in areas near the Gulf of Carpentaria the towns of Dajarra and Cloncurry in far northwestern Queensland. The last native speaker died in 1980. It is a suffixing agglutinative language with no attested prefixes.
Warluwarra is an extinct Australian Aboriginal language of Queensland. Waluwarra has a traditional language region in the local government area of Shire of Boulia, including Walgra Station and Wolga, from Roxborough Downs north to Carandotta Station and Urandangi on the Georgina River, on Moonah Creek to Rochedale, south-east of Pituri Creek.
Arrernte or Aranda or sometimes referred to as Upper Arrernte, is a dialect cluster in the Arandic language group spoken in parts of the Northern Territory, Australia, by the Arrernte people. Other spelling variations are Arunta or Arrarnta, and all of the dialects have multiple other names.
The Ngarna or Warluwar(r)ic languages are a discontinuous primary branch of the Pama–Nyungan language family of Australia. The moribund Yanyuwa language is the only survivor of this group.
Wagaya (Wakaya) is an extinct Australian Aboriginal language of Queensland. Yindjilandji (Indjilandji) may have been a separate language. The linguist Gavan Breen recorded two dialects of the language, an Eastern and a Western variety, incorporating their description in his 1974 grammar.
Wanggamala, also spelt Wanggamanha, Wangkamahdla, Wangkamadla, Wangkamanha, Wangkamana, Wonkamala, Wongkamala, Wonkamudla, and other variants, is an extinct Australian Aboriginal language of the Pama–Nyungan family, previously spoken in the Northern Territory around Hay River and to the south of the Andegerebinha-speaking area.
Yandruwandha is an Australian Aboriginal language of the Pama–Nyungan family. Yawarawarga is considered a dialect by Dixon (2002), a closely related language by Bowern (2001). It is also known as Yawarrawarrka,Yawarawarka, Yawarawarga, Yawarawarka, Jauraworka, and Jawarawarka).
Tsunoda Tasaku is a Japanese linguist, specializing in Australian Aboriginal languages. His interests embrace linguistic typology and endangered languages.
The Yandruwandha, alternatively known as Jandruwanta, are an Aboriginal Australian people living in the Lakes area of South Australia, south of Cooper Creek and west of the Wangkumara people.
The Warruŋu, also known as the Warungu/Warrongo, were an Indigenous Australian people of the northern Queensland rainforest areas south of Cairns.
The Goeng or Gureng were an Aboriginal Australian people of the state of Queensland. They lived in the area of the area of present-day Gladstone.
The Bidia, also called Biria, are an Aboriginal Australian people of the central west and western regions of the state of Queensland. Their language is known as Pirriya.
The Wadjabangai, otherwise known as Wadjabangayi, were an indigenous Australian people of Queensland.
The Koa (Guwa) are Australian Aboriginal people and Native Title Holders of land in the Upper Diamantina River catchment area in the state of Queensland that includes the towns of Winton, Kynuna, Corfield and Middleton.
The Kulumali were an indigenous Australian people of the state of Queensland.
The Marulta were an indigenous Australian people of the state of Queensland, Australia.
The Yalarnnga, also known as the Jalanga, are an Indigenous Australian people of the state of Queensland.
Burrandilla County is a cadastral division of Queensland and a County of the Warrego Land District of south western Queensland. The county is divided into civil parishes.
Palmer County is a cadastral division of Queensland and a County of the Warrego Land District of southwestern Queensland.