Dayton is a city located in Yamhill County within the state of Oregon, United States. It sits in the Willamette Valley, positioned approximately twenty-five miles southwest of Portland and seven miles east of McMinnville. The municipality occupies a total area of 0.84 square miles, all of which is land, according to the United States Census Bureau. As an incorporated city, it serves as a distinct administrative entity within the broader regional geography of the Pacific Northwest.

The city was founded in 1850 by Andrew Smith and Joel Palmer, who established a flour mill there. It was named for Smith's hometown of Dayton, Ohio. A post office opened in 1851 with Christopher Taylor as postmaster. The settlement features historic landmarks such as the Joel Palmer House, built between 1852 and 1857, which has been on the National Register of Historic Places since March 16, 1987. The Fort Yamhill Block House was moved to Dayton in 1911 to prevent demolition.

Dayton is characterized by its historic structures and rural community setting. The Joel Palmer House now houses a four-star restaurant, while the Fort Yamhill Block House stands in Courthouse Square Park. The city maintains a small-town atmosphere with three schools in the Dayton School District, including Dayton High School, whose mascot is the Pirate. The area also features the Dayton Aviation Heritage Park, reflecting its connection to aviation history.

The local economy relies heavily on agriculture, including vegetable, berry, nut, and dairy production. Vineyards and wineries in the Willamette Valley AVA and Dundee Hills AVA provide increasing economic activity and attract visitors. The community offers cultural sites such as the historic house museum and the aviation heritage park. These attractions, combined with the rural landscape, define the visitor experience and local identity.

The population was 2,678 at the 2020 census, with a median age of 34.8 years. Transportation access is provided by Oregon Routes 18, 221, and 233, along with unsigned Route 154. The city experiences a humid continental climate with four distinct seasons, including cold winters and hot, humid summers. This profile supports its role as a rural community with growing tourism ties to the surrounding wine country.