Seaham is a suburb of the Port Stephens local government area in the Hunter Region of New South Wales, Australia. It is located on the Williams River which flows into the Hunter River 14.6 km (9.1 mi) downstream from Seaham village at Raymond Terrace.
It is a rural community supporting a small but expanding population. While the actual village of Seaham, which is located in the north-eastern corner of the suburb, is relatively compact and composed of only a handful of streets, the suburb itself covers an area of approximately 42.8 km2 (16.5 sq mi). At the 2011 census, Seaham had a population of 1,025. Greater Seaham covers an even larger area and incorporates East Seaham, Brandy Hill, Eagleton and Eskdale Estate.