The son of Eli and Mary Gosnell, he was born at Arrandale Cannery and grew up in the village of New Aiyansh where he still lives. He received his formal education at St. Michael's Residential School in Port Alberni, British Columbia. As a young man he worked as a fisherman. He later served as band councillor and became active in the Native Brotherhood of British Columbia, of which he eventually became chairman. He was also a member of the Pacific Salmon Commission. He served for many years on the Nisga'a Tribal Council, of which he was elected President in 1992. In these various positions he was instrumental in bringing modern medical care, education, and resource management to the Nass River Valley. He was the chief Nisga'a representative in the negotiations that led to the signing of the Nisga'a Treaty  on 4 August 1998, the first modern treaty between a British Columbia First Nation, Canada, and British Columbia. In November, 2000 he was elected President of the new Nisga'a Lisms government.
A fluent speaker of the Nisga'a language, he is a member of the Gitlaxt’aamiks Ceremonial Dancers. He holds the noble name Sim'oogit Hleek. He is married to the former Audrey Adele Munroe with whom he has seven children: Marilyn Arlene, Joseph Wayne, Sharon Marjorie, Theodore Allen, Frank Curtis, Keith Andrew and Kevin Wesley.
He received an Honorary Doctorate of Laws Degree from Royal Roads University in Colwood, near Victoria on October 17, 1997, one from the Opening Learning Agency in Burnaby on May 7, 1999, one from Simon Fraser University in 2000 and one from the University of Northern British Columbia on May 26, 2000. He received the Humanitarian Award from the Canadian Labour Congress in Toronto on May 6, 1999.
In 1999 he received the Order of British Columbia. In 2000, Chief Gosnell received the Lifetime Achievement Award from the National Aboriginal Achievement Foundation. 2001, he was named an Officer of the Order of Canada and was promoted to Companion in 2006. In 2002 he received the Queen's Golden Jubilee Medal.
- "Storytellers. First Nation Storyteller Joseph Arthur Gosnell Sr.". Iona Pacific Inter-Religious Centre. Retrieved 2012-11-29.
- "Biography – Chief Joseph Gosnell". Nisga'a Chief Joseph Council. Retrieved 2012-11-29.
- "Biography, Chief Joseph Gosnell, The Governor General's Canadian Leadership Conference". Nisfa'a Chief Joseph Council. Retrieved 2012-11-29.
- Order of Canada citation
- Gosnell speech of 1998-12-02
- Order of British Columbia citation
- Canada Gazette Part I, Vol. 135, No. 13
- Gosnell speech on signing of treaty
- Joseph Gosnell Biography
- Rose, Alex (2001) Spirit Dance at Meziadin: Chief Joseph Gosnell and the Nisga'a Treaty. Madeira Park, British Columbia: Harbour Publishing. ISBN 1-55017-244-1