Madison is a city in Jefferson County, Indiana, United States, serving as the county seat. It sits along the north side of the Ohio River, bordered to the south by Milton, Kentucky. The city occupies a strategic position on the historic Old Michigan Road and functions as an entry point into the Indiana Territory. Its location across the river from a former slave state made it significant during the era of the Underground Railroad.

The city was laid out and platted in 1810, with lots sold by John Paul in 1811. It grew rapidly due to river traffic and became the third-largest city in Indiana by 1850. Indiana's first railroad, the Madison & Indianapolis Railroad, was built there between 1836 and 1847. In 2006, the majority of the downtown area was designated a National Historic Landmark, encompassing 133 blocks known as the Madison Historic Landmark District.

The historic district contains examples of nineteenth and early twentieth-century architectural styles, ranging from Federal to Art Moderne. The Jefferson County Courthouse features a dome that was rebuilt after a fire in 2009 caused by contractor work. Nearby Clifty Falls State Park encompasses the canyon of Big Clifty Creek with waterfalls rising above the river valley. The town of North Madison was annexed in 1952 and later suffered damage from an F4 tornado during the 1974 Super Outbreak.

Madison offers a blend of historical preservation and natural beauty, attracting visitors to its scenic byways and historic architecture. The Madison Area Chamber of Commerce, founded in 1924, supports local business growth. The city's heritage is marked by its role in the abolitionist movement and its early industrial development. Today, it retains a small-town feel while preserving its rich architectural legacy for educational and tourism purposes.

As of the 2020 census, Madison had a population of 12,357. The median age was 42.9 years, with 92.5% of residents living in urban areas. U.S. Route 421 passes through the center, crossing into Kentucky via the Milton–Madison Bridge. The climate is humid subtropical, characterized by hot, humid summers and mild to cool winters. The city remains a key cultural and administrative hub in southern Indiana.