Ridgefield is a city situated in northern Clark County within the state of Washington, United States. It lies inside the Portland metropolitan area and occupies a total area of 7.674 square miles, comprising 7.599 square miles of land and 0.075 square miles of water. The community serves as the headquarters for the Ridgefield National Wildlife Refuge, a significant reserve for migrating waterfowl on the Pacific Flyway. Its geographic position near the mouth of the Columbia River has historically defined its role as a regional hub.

The area contains the site of Cathlapotle, a Chinookan village occupied since 1450 that served as a fur trade center by 1792. White settlers began filing land claims under the Donation Land Claim Act in 1850, establishing Shobert's Landing. The community was renamed Union Ridge in the 1860s to reflect pro-Union sentiments during the Civil War before being renamed Ridgefield in 1890 by a postmaster who wished to avoid political references. It incorporated as a city in 1909.

The city is defined by its potato-farming heritage, reflected in the Ridgefield High School mascot, the Spudders. Notable landmarks include the replica Cathlapotle plank house dedicated at the wildlife refuge in 2005 and the historic Presbyterian church on Main Avenue built in 1883. Parks such as Abrams, Community, Davis, and Overlook provide green space, while the Ridgefield Veterans Memorial stands adjacent to Community Park. The area also features the site of the former Pacific Wood Treating plant.

Visitor appeal centers on the deep Native American history and the connection to the Lewis and Clark Expedition of 1804–1806. The Ridgefield National Wildlife Refuge attracts nature enthusiasts seeking to observe nesting grounds for Canada geese and other waterfowl. Cultural institutions include the Ridgefield Reflector newspaper, which began publication in 1909, and local schools that preserve the town's historical narrative through their names and community engagement.

The population was 10,319 at the 2020 census, with estimates reaching 16,132 by 2025. The economy includes major employers such as U-Haul, founded in 1945, and retail locations like Costco and In-N-Out Burger. Access to the city was significantly improved by the arrival of Interstate 5 in the 1960s and a railroad built in 1903. The median household income is reported at $116,389, indicating a robust local economic profile.