The Otago Peninsula is a long, rugged indented finger of land that forms the easternmost part of Dunedin, New Zealand. Volcanic in origin, it forms one wall of the collapsed crater that now forms Otago Harbour. The peninsula lies due east of Otago Harbour and runs parallel to the mainland for 30 km. Its maximum width is 12 km. It is joined to the mainland at the south-west end by a narrow isthmus a little over one kilometre in width.
The suburbs of Dunedin encroach onto the western end of the peninsula, but for the majority of its length it is sparsely populated and occupied by steep open pasture. The peninsula is home to many species of wildlife, notably seabirds, and ecotourism is an increasingly important part of its economy.
The peninsula was formed at the same time as the hills that face it across the harbour, as part of the crater wall of a large, long-extinct, volcano. Several of the peninsula's peaks, notably the aptly-named Harbour Cone, clearly show these volcanic origins in their form. These rocks were built up between 13 and 10 million years ago.
Much of the peninsula is steep hill country, with the highest points being Mount Charles (408 m), Harbour Cone, and Sandymount. Two tidal inlets dominate the Pacific coast of the peninsula, Hoopers Inlet and Papanui Inlet. Between them is the headland of Cape Saunders. Nearby natural features include the 250-m-high cliffs of Lovers' Leap and The Chasm.