Longbranch is an unincorporated community in Pierce County, Washington, United States. It is located on the Key Peninsula, along Filucy Bay between Pitt Passage and Balch Passage. Longbranch is primarily residential (like nearby Home and Lakebay) and includes a marina, church, and community centre. Longbranch was named for Long Branch, New Jersey.
In 1934, Longbranch was linked by ferry service with Steilacoom, Anderson and McNeil islands. The ferry continues in operation, but no longer connects to Longbranch.