The D'Entrecasteaux Channel /ˌdɒntrəˈkæstoʊ/ is a body of water located between Bruny Island and the south-east of the mainland of Tasmania, Australia.

The channel is the mouth for the estuaries of the Derwent and the Huon Rivers and empties into the Tasman Sea of the South Pacific Ocean.

According to The Mercury newspaper, the channel "..... was discovered on 20 April 1792 by the celebrated French "Vice-Admiral Bruni D'Entrecasteaux, who, in the ships Recherche and Esperance, was searching for ill-fated La Perouse.

Visiting Van Diemen's Land for the first time, he was attempting to find an anchorage in Adventure Bay, when, being himself ill in bed, the ships' navigators entered the channel to the west of Bruny Island, instead of going to the eastward of it.

[5] The D'Entrecasteaux Channel region sheltered by Bruny Island is increasingly affected by foreshore erosion, in some areas sandbagging aims to reduce the effects.