The Seaside Museum and Historical Society was founded in 1974 by a group of local residents who wanted to celebrate and share the rich history of the community. 

The museum began in a small storefront in downtown Seaside, but as the collection grew, the membership decided a permanent location was needed. A city lot was leased and a building erected and the museum opened in November 1983 at its current location.

The museum moved the historic Butterfield Cottage to the museum grounds in 1984 and began a comprehensive restoration of the building. The museum officially opened its new exhibit, the oldest beach cottage museum on the Oregon coast, in 1991.

Today, the Seaside Museum and Historical Society is home to a wide variety of exhibits and artifacts that showcase the history of Seaside and the surrounding area. The museum's collection includes photographs, documents, artifacts, and other materials that tell the story of the town's development from a remote beach village to a thriving tourist destination.  Visitors to the museum can explore exhibits on a wide range of topics, including the area's Native American history, the Lewis and Clark Expedition, and the growth of Seaside as a resort town. The museum also offers educational programs, tours, and special events throughout the year.