Hiawatha (Ioway: Hári Wáta pronounced [haːꜜɾi waːꜜtʰɐ]) is the largest city in and the county seat of Brown County, Kansas, United States. As of the 2020 census, the population of the city was 3,280.

B.L. Rider reportedly was responsible for naming Hiawatha, taking the young Indian's name from Henry Wadsworth Longfellow's poem, The Song of Hiawatha. In the poem is legendary Onondaga and Mohawk Indian leader Hiawatha. Adjacent to the former Ioway-Sac reservation and the present-day Ioway Tribe of Kansas and Nebraska, Hiawatha is called Hári Wáta in Ioway, meaning "I am looking far away".

Hiawatha was founded in 1857, making it one of the oldest towns in the state. John M. Coe, John P. Wheller, and Thomas J. Drummond were instrumental in organizing the city, and the site was staked out February 17, 1857. Hiawatha became the Brown County Seat in 1858, and the first school opened in 1870.

The main street was designated Oregon Street after the Oregon Trail. Parallel streets north of it were named after Indian tribes north of the Trail, and streets south carried tribal names of those south of the Trail.

The city is home to the longest running continuous Halloween parade in the nation, starting in 1914.

According to The New York Times in 2012, "the cartoonist Bob Montana inked the original likenesses of Archie and his pals and plopped them in an idyllic Midwestern community named Riverdale because Mr. [John] Goldwater, a New Yorker, had fond memories of time spent in Hiawatha" Goldwater had hitchhiked to the community at the age of 17 and started working at the Hiawatha Daily World.

According to the United States Census Bureau, the city has a total area of 2.59 square miles (6.71 km²), all land.

According to the Köppen Climate Classification system, Hiawatha has a hot-summer humid continental climate, abbreviated "Dfa" on climate maps.