Madison is the capital of the U.S. state of Wisconsin. It is the second-most populous city in the state, with a population of 269,840 at the 2020 census. The Madison metropolitan area has an estimated 708,000 residents. With a downtown centrally located on an isthmus between Lakes Mendota and Monona, the city also encompasses Lake Wingra. Madison was founded in 1836 and is named after American Founding Father and President James Madison. It is the county seat of Dane County.

As the state capital, Madison is home to government chambers, including the Wisconsin State Capitol. It is also home to the University of Wisconsin–Madison, the flagship campus of the University of Wisconsin System. Major companies in the city include American Family Insurance and TruStage Financial Group. Tourism also plays a vital role in the local economy, generating over $1 billion in 2018. The city features a variety of cultural and recreational institutions, including the Chazen Museum of Art, Henry Vilas Zoo, Olbrich Botanical Gardens, and Overture Center for the Arts.

As of 2024, Madison is the fastest-growing city in the state. The city has a longstanding reputation for progressive political activity and is regarded as Wisconsin's most politically liberal city. The presence of the University of Wisconsin–Madison and other educational institutions significantly shapes the local economy, culture, and demographics. Madison boasts one of the highest numbers of parks and playgrounds per capita among the 100 largest U.S. cities and is widely recognized as a bicycle-friendly community. Within the city are nine National Historic Landmarks, including several buildings designed by Frank Lloyd Wright.

Before Europeans, humans inhabited the area in and around Madison for about 12,000 years. The Ho-Chunk called the region Teejop (Ho-Chunk pronunciation: [teːdʒop]) meaning 'land of the four lakes' (Mendota, Monona, Waubesa, and Kegonsa). Numerous effigy mounds, constructed for ceremonial and burial purposes more than 1,000 years earlier, dotted the rich prairies around the lakes. Dugout canoes found near many small lakes and rivers are prompting new anthropological research projects.

Madison's modern origins begin in 1829, when former federal judge James Duane Doty purchased over a thousand acres (4 km²) of swamp and forest land on the isthmus between Lakes Mendota and Monona, with the intention of building a city in the Four Lakes region. He purchased 1,261 acres for $1,500. When the Wisconsin Territory was created in 1836 the territorial legislature convened in Belmont, Wisconsin. One of the legislature's tasks was to select a permanent location for the territory's capital. Doty lobbied aggressively for Madison as the new capital, offering buffalo robes to the freezing legislators and choice lots in Madison at discount prices to undecided voters. He had James Slaughter plat two cities in the area, Madison and "The City of Four Lakes", near present-day Middleton.

Doty named his city for James Madison, the fourth President of the U.S., who had died on June 28, 1836, and he named the streets for the other 38 signers of the U.S. Constitution. Although the city existed only on paper, the territorial legislature voted on November 28, 1836, to make Madison its capital, largely because of its location halfway between the new and growing cities around Milwaukee in the east and the long-established strategic post of Prairie du Chien in the west, and between the highly populated lead mining regions in the southwest and Wisconsin's oldest city, Green Bay, in the northeast.

The cornerstone for the Wisconsin capitol was laid in 1837, and the legislature first met there in 1838. On October 9, 1839, Kintzing Prichett registered the plat of Madison at the registrar's office of the then-territorial Dane County. Madison was incorporated as a village in 1846, with a population of 626. When Wisconsin became a state in 1848, Madison remained the capital, and in 1849 it became the site of the University of Wisconsin (now University of Wisconsin–Madison). The Milwaukee & Mississippi Railroad (a predecessor of the Milwaukee Road) connected to Madison in 1854. Madison incorporated as a city in 1856, with a population of 6,863, leaving the unincorporated remainder as a separate Town of Madison. The original capitol was replaced in 1863 and the second capitol burned in 1904. The current capitol was built between 1906 and 1917.

During the Civil War, Madison served as a center of the Union Army in Wisconsin. The intersection of Milwaukee, East Washington, Winnebago, and North Streets is known as Union Corners because a tavern there was the last stop for Union soldiers before leaving to fight the Confederates. Camp Randall, on Madison's west side, was built and used as a training camp, a military hospital, and a prison camp for captured Confederate soldiers. After the war, the Camp Randall site was absorbed into the University of Wisconsin, and Camp Randall Stadium was built there in 1917. In 2004 the last vestige of active military training on the site was removed when the stadium renovation replaced a firing range used for ROTC training.^{[citation needed]}