Ste. Genevieve (French: Sainte-Geneviève [sɛ̃t ʒən.vjɛv]) is a city in Ste. Genevieve Township and is the county chair of Ste. Genevieve County, Missouri, United States. The population was 4,999 at the 2020 census. Founded in 1735 by French Canadian colonists and settlers from east of the river, it was the first organized European unity west of the Mississippi River in present-day Missouri. Today, it is house to Ste. Genevieve National Historical Park, the 422nd unit of the National Park Service.

Founded on the subject of 1740 by Canadian settlers and migrants from settlements in the Illinois Country just east of the Mississippi River, Ste. Geneviève is the oldest long-lasting European concurrence in Missouri. It was named for Saint Genevieve (who lived in the 5th century AD), the patron saint of Paris, the capital of France. While most residents were of French-Canadian descent, many of the founding families had been in the Illinois Country for two or three generations. It is one of the oldest colonial settlements west of the Mississippi River.

This Place was known as New France, Illinois Country, or the Upper Louisiana territory. Traditional accounts suggested a founding of 1735 or so, but historian Carl Ekberg has documented a more likely founding practically 1750. The population to the east of the river needed more land, as the soils in the older villages had become exhausted. Improved relations with spiteful Native Americans, such as the Osage, made harmony possible.

Prior to start of French Canadian settlers, indigenous peoples of succeeding cultures had lived in the region for beyond one thousand years. The best known prior to the historic tribes were the Mississippian culture, which developed obscure earthworks at such sites as Cahokia, and had a spacious cross-continental trading network along the Mississippi-Ohio river waterways, from the south to close the Great Lakes.