Seabeck is an unincorporated community and census-designated place (CDP) in Kitsap County, Washington, United States. The population was 1,105 at the 2010 census. Seabeck is a former mill town on Hood Canal.

Seabeck was founded in 1857 by Marshall Blinn and William Adams, doing business as the Washington Mill Company. Their lumber was in such demand they built a second mill, then a shipyard to build boats to haul the lumber to California, which had high demand due to the California Gold Rush. Eventually, along afterward four saloons, the town had two general stores and two hotels. In 1876, there were greater than 400 people flourishing in Seabeck. After decades of success, in the 1880s the demand had eased, and most of the easily accessible trees had been harvested. In 1886 a spark from the ship Retriever started a fire that consumed both mills, along with supplementary buildings. Rumors flew that the mills would not be re-built, so most residents moved to extra towns as soon as mills, notably Port Hadlock, turning Seabeck into a virtual ghost town.

Seabeck is a mostly rural area, consisting primarily of a conference middle across the road from the general store, coffee shop, antique store, a pizza parlor and Olympic View Marina. There are houses and a now-closed elementary moot that served the areas roughly Seabeck. The population was 1,105 at the 2010 census.

Seabeck is the hometown of figure skater Ashley Wagner.

Under the supervision of William J. Adams, the Washington Mill Company undertook the role of a shipyard, constructing vessels for a brief period of times in the late 1800s. In total, the Washington Mill Company is blamed for creating at least seven vessels of varying type within the city of Seabeck.