Queen Charlotte Sound is the easternmost of the main sounds of the Marlborough Sounds, in New Zealand's South Island. It is, like the other sounds, a drowned river valley, and like the majority of its neighbours it runs southwest to northeast before joining Cook Strait. The town of Picton, the northern terminus of the South Island's railway and State Highway networks, lies near the head of the Sound. Other settlements by the sound are small and isolated - often simply individual properties.