Lyttelton Harbour / Whakaraupō is a major inlet on the northwest side of Banks Peninsula, on the coast of Canterbury, New Zealand; the other major inlet is Akaroa Harbour, which enters from the southern side of the peninsula. Whakaraupō enters from the northern coast of the peninsula, heading in a predominantly westerly direction for approximately 15 km (9.3 mi) from its mouth to the aptly-named Head of the Bay near Teddington. The harbour sits in an eroded caldera of the ancient Banks Peninsula Volcano, the steep sides of which form the Port Hills on its northern shore.

Banks Peninsula is a peninsula of volcanic origin on the east coast of the South Island of New Zealand. It has an area of approximately 1,150 square kilometres (440 sq mi) and encompasses two large harbours and many smaller bays and coves. The South Island's largest city, Christchurch, is immediately north of the peninsula.