Ngadjuri is a single-member electoral district for the South Australian House of Assembly. A rural district in Mid North region, it runs from the Gawler River and Gulf St Vincent in the south, through farming areas, to Clare in the north. It includes towns of Two Wells, Dublin, Mallala, Wasleys, Roseworthy, Freeling, Hamley Bridge, Owen, Tarlee, Riverton, Marrabel, Marrabel, Kapunda, Point Pass, Eudunda, Saddleworth, Auburn, Manoora, Robertstown, Robertstown and Watervale.
The electorate was created in the 2024 redistribution of electoral boundaries and was first contested at the 2026 election. A reconfigured version of Frome, its name "Ngadjuri", is a Aboriginal word meaning "we people".
A significant redrawing of the boundaries occurred between Frome and Ngadjuri with the electorate gaining around 3,200 voters from Light near Gawler and losing around 3,600 voters in the Northern Areas Council, including Jamestown and Spalding, as well as part of the Regional Council of Goyder to Stuart. Also 1,650 voters in Watchman, Balaklava, South Australia, Dalkley, Hoskin Corner and Erith were transferred into Narungga. Ngadjuri lost conservative areas in the north and gained Labor-leaning areas near Gawler, significantly cutting the Liberal margin from 8.1 to 3.2 per cent.
The 2026 election was contested by Tony Piccolo, the Deputy Speaker of the House of Assembly and the Labor MP for the neighbouring seat of Light and sitting Liberal MP for Frome, Penny Pratt. Both were defeated by the One Nation candidate, the Deputy Mayor of the Adelaide Plains Council, David Paton to secured the first lower house seat in the Assembly for the conservative minor party.