alt=Main Street 1943|thumb|Main Street 1943
Decorah is the largest city in and the county seat of Winneshiek County, Iowa, United States. The population was 7,587 at the time of the 2020 census. Decorah is the home of Luther College, a private liberal arts college. It is known for its Norwegian-American heritage and the corresponding Vesterheim Norwegian-American Museum.
Decorah is located at the intersection of State Highway 9 and U.S. Route 52. Located within the Driftless Area in northeastern Iowa, Decorah is situated in the bluffs of the Upper Iowa River, which flows through the city. In 1848, the United States removed the Ho-Chunks again to a new reservation in Minnesota, opening their Iowa villages to white settlers.
thumb|upright|left|Chief [[Waukon Decorah in 1825]]
thumb|350px|center|Panoramic view of Decorah, 1908
The first European-Americans to settle were the Day family from Tazewell County, Virginia. According to local Congregationalist minister Rev. Ephraim Adams, the Days arrived in June 1849 with the Ho-Chunks' "tents still standing—with the graves of the dead scattered about where now run our streets and stand our dwellings." Judge Eliphalet Price suggested that the Days name their new settlement Decorah after Ho-Chunk leader Waukon Decorah, who was a U.S. ally during the Black Hawk War of 1832.
During the 1850s and 1860s, Decorah grew quickly as settlers built dams and mills to harness water power at Dunning's Spring and other local streams. In 1851, the town became the county seat of Winneshiek County. Decorah also became the site of a United States General Land Office from 1855 to 1856, making it a destination for immigrants seeking land patents in northern Iowa.
Since 1861, it has been the home of Luther College, a liberal arts institution affiliated with the Evangelical Lutheran Church in America.
The Milwaukee and St. Paul Railroad opened a branch to Decorah in 1869.
Decorah has become a center for Norwegian-American culture originating from a high number of Norwegian settlements beginning in the 1850s. Each July, Decorah is the host of Nordic Fest, a celebration of Norwegian culture with ethnic dancing, food, and music. Decorah is also the home of the Vesterheim Norwegian-American Museum, the largest museum in the country devoted to a single immigrant group.
Geography
Decorah is located approximately south of the Minnesota-Iowa border. It is the northernmost major community located along U.S. Route 52 in Iowa. According to the United States Census Bureau, the city has a total area of , of which is land and is water. Decorah is located in and on the bluffs of the Upper Iowa River valley; the river flows through the city en route to its confluence with the Upper Mississippi River.
The impact dug a crater nearly four miles wide that now lies beneath the town, said Bevan French, one of the world's foremost crater hunters and an adjunct scientist at the National Museum of Natural History.