Matilda Williams House (1945-)  of the Ngambri-Ngunnawal nation was born on the Erambie Aboriginal Reserve at Cowra, New South Wales (NSW), and raised in her grandfather’s house at Hollywood Aboriginal Reserve in Yass, NSW. One of 10 children,  she was  sent to the Parramatta Girls' Home for a year aged 12.

She has cultural connections to the Canberra region and surrounds, particularly the region around Namadgi National Park. Returning to Canberra in 1963 Matilda has been actively involved in Indigenous Affairs in the Canberra region since 1967.
 

Matilda is the Chair of the Ngambri Local Aboriginal Land Council in Queanbeyan, NSW, which she established with her brothers in 1984,  and the Joint Chair of the Interim Namadgi National Park Committee.

She assisted in establishing the Aboriginal Legal Service in the 1980s, and has continued more recently through her membership of the Aboriginal Justice Advisory Committee.
 

Matilda performed the first Welcome to Country to be held at the Australian Parliament at the opening of the 42nd Parliament of Australia.
 

She served on the first ACT Heritage Council, the United Ngunnawal Elders Council, the Queanbeyan Regional Council of the Aboriginal and Torres Strait Islander Commission (ATSIC), the Ngambri Local Aboriginal Land Council, the Tent Embassy Advisory Committee and the ACT Aboriginal and Torres Strait Islander Community Consultative Council. She has also acted as an ACT honorary ambassador.

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House's involvement in Indigenous Affairs led to her delivering the welcome at Australians for Native Title and Reconciliation's ‘Sea of Hands’ installation, and contributing to the 'Bringing Them Home' report into the Stolen Generations.[16] She was also one of the original protestors who established the Aboriginal Tent Embassy in 1972 and stood in opposition to Senator Ian MacDonald in his call for its removal.
 

House was named Canberra Citizen of the Year in 2006.