Saint Paul (often abbreviated St. Paul) is the capital city of the U.S. state of Minnesota and the county seat of Ramsey County. As of the 2020 census, the city had a population of 311,527, making it Minnesota's second-most populous city and the 63rd-most populous in the United States. Saint Paul and neighboring Minneapolis form the core of the Twin Cities metropolitan area, the third most populous in the Midwest with around 3.7 million residents.

The Minnesota State Capitol and the state government offices sit on a hill next to downtown Saint Paul overlooking a bend in the Mississippi River. Local cultural offerings include the Science Museum of Minnesota, the Ordway Center for the Performing Arts, and the Minnesota History Center. Three of the region's professional sports teams play in Saint Paul: the Minnesota Wild and Frost (at the Grand Casino Arena) and Minnesota United FC (at Allianz Field). The minor-league baseball team the St. Paul Saints play at CHS Field, 10 miles (16 km) from their major-league affiliate the Minnesota Twins in downtown Minneapolis.

The Legislative Assembly of the Minnesota Territory established the Town of Saint Paul as its capital near existing Dakota Sioux settlements in November 1849. Named after a log chapel established by Lucien Galtier, it remained a town until 1854. The city rose to prominence as the headquarters of 19th-century industrialist James J. Hill's railroad empire, with his transcontinental Great Northern Railway then one of the nation's most dominant. Saint Paul has a mayor–council government. The mayor is Melvin Carter III, who was first elected in 2018.

Burial mounds in present-day Indian Mounds Park suggest the area was inhabited by the Hopewell Native Americans about 2,000 years ago. From the early 17th century to 1837, the Mdewakanton Dakota, a band of the Dakota people, lived near the mounds at the village of Kaposia and consider the area encompassing present-day Saint Paul Bdóte, the site of creation for their people. The Dakota called the area Imniza-Ska ('white cliffs') for its exposed white sandstone cliffs on the river's eastern side. The Imniza-Ska were full of caves that were useful to the Dakota. The explorer Jonathan Carver documented the historic Wakan Tipi in the bluff below the burial mounds in 1767. In the Menominee language Saint Paul was called Sāēnepān-Menīkān, which means 'ribbon, silk or satin village', suggesting its role in trade throughout the region after the introduction of European goods.

After the 1803 Louisiana Purchase, U.S. Army Lieutenant Zebulon Pike negotiated approximately 100,000 acres (40,000 ha; 160 sq mi) of land from the indigenous Dakota in 1805 to establish a fort. A military reservation was intended for the confluence of the Mississippi and Minnesota rivers on both sides of the Mississippi up to Saint Anthony Falls. All of what is now the Highland Park neighborhood was included in this. Pike planned a second military reservation at the confluence of the St. Croix and Mississippi rivers. In 1819, Fort Snelling was built at the Minnesota and Mississippi confluence. The 1837 Treaty with the Sioux ceded all tribal lands east of the Mississippi to the U.S. government. Chief Little Crow III moved his village, Kaposia, from south of Mounds Park across the river a few miles onto Dakota land. Fur traders, explorers, and settlers came to the area for the fort's security. Many were French-Canadians who predated American pioneers by some time. A whiskey trade flourished among the squatters and the fort's commander evicted them all from the fort's reservation. Fur trader turned bootlegger "Pig's Eye" Parrant, who set up business just outside the reservation, particularly irritated the commander. By the early 1840s, a community had developed nearby that locals called "Pig's Eye" (French: L'Œil du Cochon) or "Pig's Eye Landing" after Parrant's popular tavern. In 1842, a raiding party of Ojibwe attacked the Kaposia encampment south of Saint Paul. A battle ensued where a creek drained into wetlands two miles south of Wakan Tipi. The creek was thereafter called Battle Creek and is today parkland. In the 1840s-70s the Métis brought their oxen and Red River Carts down Kellogg Street to Lambert's landing to send buffalo hides to market from the Red River of the North. Saint Paul was the southern terminus of the Red River Trails.

In 1841, Catholic missionary Lucien Galtier was sent to minister to the French Canadians at Mendota. He had a chapel he named for St. Paul built on the bluff above the riverboat landing downriver from Fort Snelling. Galtier informed the settlers that they were to adopt the chapel's name for the settlement and cease the use of "Pig's Eye". In 1847, New York educator Harriet Bishop moved to the settlement and opened the city's first school. The Minnesota Territory was created in 1849 with Saint Paul as the capital. The U.S. Army made the territory's first improved road, Point Douglas Fort Ripley Military Road, in 1850. It passed through what became Saint Paul neighborhoods. In 1857, the territorial legislature voted to move the capital to Saint Peter, but Joe Rolette, a territorial legislator, stole the text of the bill and went into hiding, preventing the move.

The year 1858 saw more than 1,000 steamboats service Saint Paul, making it a gateway for settlers to the Minnesota frontier or Dakota Territory. Geography was a primary reason the city became a transportation hub. The location was the last good point to land riverboats coming upriver due to the river valley's topography. For a time, Saint Paul was called "The Last City of the East". Fort Snelling was important to Saint Paul from the start. Direct access from Saint Paul did not happen until the 7th bridge was built in 1880. Before that, there was a cable ferry crossing dating to at latest the 1840s. Once streetcars appeared, a new bridge to Saint Paul was built in 1904. Until the town built its first jail the fort's brig served Saint Paul. Industrialist James J. Hill founded his railroad empire in Saint Paul. The Great Northern Railway and the Northern Pacific Railway were both headquartered in Saint Paul until they merged with the Burlington Northern. Today they are part of the BNSF Railway.

On August 20, 1904, severe thunderstorms and tornadoes damaged hundreds of downtown buildings, causing $1.78 million ($62.29 million today) in damages and ripping spans from the High Bridge. During the 1960s, in conjunction with urban renewal, Saint Paul razed neighborhoods west of downtown for the creation of the interstate freeway system. From 1959 to 1961, the Rondo neighborhood was demolished for the construction of Interstate 94. The loss of that African American enclave brought attention to racial segregation and unequal housing in northern cities. The annual Rondo Days celebration commemorates the African American community.