The Nggamadi were an indigenous Australian people of the Cape York Peninsula of northern Queensland.
They are often conflated with the Ankamuti, but Tindale regarded them as a separate tribal reality. Terry Crowley writes: <blockquote>In the region referred to locally as the "Seven Rivers" area (the seven rivers being the Jardine, MacDonald, Skardon, Doughboy, Ducie and Jackson Rivers, and Crystal Creek), which constitutes the very narrow coastal stretch from the northern side of Port Musgrave as far as the Doughboy River, and also the inland area of Crystal Creek and the middle Jardine River, were the aà Âkamuṯi -speaking people. The non-coastal aà Âkamuṯi of the Jardine River were alternatively called yampaãuëaà Âu or utuðanamu (meaning "leaf people" and "scrub dwellers" respectively). The aà Âkamuṯi have previously been referred to in the literature by the name à Âkamuṯi (Gamiti in Roth 1910:96), Ngkamadyi in McConnel (1939-1940:60) and Nggammadi in Sharp (1939:257), which was used for the aà Âkamuṯi by the CV-dropping groups to the south of Port Musgrave (Crowley 1981:146).</blockquote>
Norman Tindale estimated that the Nggamadi had about of territory. They lay north of the Dulhunty River as far as around Vrilya Point (Cockatoo Creek), and were present also at the Jackson and Skardon rivers.