Seabrook is an unincorporated planned community in Grays Harbor County, Washington, United States. Founded in 2004 by developers Casey and Laura Roloff, Seabrook is a beach town based on the concept of New Urbanism.

Seabrook has a town hall, a Montessori school, and as of 2023 had 18 parks. A majority of its homes are vacation rentals. A grocery store and business district opened in 2023. A major expansion with 1,300 homes and a hotel began construction in 2023 and is scheduled to be completed in 2025. Future plans include a medical clinic, school, and a regenerative farm.