The Adelaide Plains (Kaurna name Tarndanya) is a plain in South Australia lying between the coast (Gulf St Vincent) on the west and the Mount Lofty Ranges on the east. The southernmost tip of the plain is in the southern seaside suburbs of Adelaide around Brighton at the foot of the O'Halloran Hill escarpment with the south Hummocks Range and Wakefield River roughly approximating the northern boundary.
Traditionally entirely occupied by the Kaurna (indigenous) people, the Adelaide Plains are crossed by a number of rivers and creeks, but several dry up during summer. The rivers (from south to north) include: the Onkaparinga/Ngangki, Sturt/Warri Torrens/Karra Wirra, Little Para, Gawler, Light/Yarralinka and Wakefield/Undalya. The plains are generally fertile with annual rainfall of about 460 millimetres (18 in) per year.