Seaforth is a suburb of northern Sydney, in the
state of New South Wales, Australia. Seaforth
is located 12 kilometres north-east of the Sydney
central business district in the local government
area of Northern Beaches Council and is part of
the Northern Beaches region.

Seaforth overlooks Middle Harbour and is linked
south to Mosman by the Spit Bridge. To the west,
Seaforth overlooks Sugarloaf Bay across to the
suburbs of Northbridge, Castlecrag and Castle
Cove.
The Garigal National Park sits on the northern
border.