Green Bay is a city in Brown County, Wisconsin, United States, and its county seat. It is located along the Green Bay inlet at the mouth of the Fox River on Lake Michigan. With a population of 107,395 at the 2020 census, it is the third-most populous city in Wisconsin and third-most populous city on Lake Michigan. The Green Bay metropolitan area has an estimated 335,000 residents.

Green Bay was settled in 1634 by Jean Nicolet as a fur trading post in New France. Its development was shaped by its location at the mouth of the Fox River and it emerged as a center for the lumber, shipping, and paper industries in the 19th and 20th centuries. In the contemporary period, Green Bay's economy encompasses manufacturing, healthcare, and service sectors. The city is widely recognized for its association with the Green Bay Packers of the National Football League, a publicly owned franchise whose presence contributes significantly to the local economy and culture.

Samuel de Champlain, the founder of New France, commissioned Jean Nicolet to form a peaceful alliance with Native Americans in the western areas, whose unrest interfered with the French fur trade, and to search for a shorter trade route to China through Canada. Nicolet and others had learned from other First Nations of the Ho-Chunk (Winnebago) people, who identified as "People of the Sea", and believed they must reside on or near an Ocean. Champlain had also heard about natural resources in the area, including fertile soil, forests, and animals. Nicolet began his journey for this new land shortly before winter in 1634. In what later became a French fur-trading route, he sailed up the Ottawa River, through Lake Nipissing and down the French River to Lake Huron, then through the straits of Michilimackinac into Lake Michigan. He is believed to have landed at Red Banks, near the site of the modern-day city of Green Bay, Wisconsin.

Nicolet founded a small trading post here in 1634, originally named La Baye or La Baie des Puants (French for "the Bay of Stinking Waters"). Nicolet's settlement was one of the oldest European permanent settlements in America. When Nicolet arrived in the Green Bay area, he encountered the Menominee, who occupied this territory. He also met the Ho-Chunk (also known as the Winnebago), a people who spoke a Siouan language.

The Winnebago hunted and fished, and also cultivated corn, beans, squash, and tobacco. Wild rice, which they had incorporated as a dietary staple, grew in abundance along the riverbanks. The women regularly harvested and cooked this, along with a wide variety of nuts, berries, and edible roots which they gathered in the woods. The men typically hunted and fished for food, and the women processed game and other foods in cooking. They prepared and made clothing from the furs, as well as using other parts of animals to make tools, cord, etc. Women also had a role in the political process, as no action could be taken without agreement of half of the women. Nicolet stayed with this tribe for about a year, becoming an ally. He helped open up opportunities for trade and commerce with them before returning to Quebec.

A few months after Nicolet returned to Quebec, Champlain died. His death halted other journeys to La Baie Verte (French for "The Green Bay"). Père Claude Allouez sent Nicolas Perrot to La Baie. After this, the French avoided the area for some decades, because of the intensity of First Nations and European conflicts in the east. In 1671, a Jesuit Mission was set up in the area. A fort was added in 1717 and gradually associated development took place. The town was incorporated in 1754. Great Britain took control of some French areas during the Seven Years' War, known as the French and Indian War in some areas of North America. They took control of this town in 1761. After the British defeated the French in 1763, France ceded its lands east of the Mississippi in North America.

The first permanent settlers were Charles Michel de Langlade and his family from Quebec, who moved to Green Bay in 1765. They are considered the first European settlers in the present-day state of Wisconsin. Langlade, called the "Founder and Father of Wisconsin", was a métis or mixed-race, son of a French-Canadian father and an Ottawa woman. He grew up with his mother's family among the Ottawa people and became a war chief. The Ottawa were allies of the French during the French and Indian War, and Langlade is credited with planning the ambush of British General Braddock and George Washington. His family was followed to Green Bay by the Grignons, Porliers and Lawes, who brought French-Canadian culture with them. Colorful "jack-knife Judge" Reaume dispensed British justice in the territory after Great Britain took it over following the war. These early ethnic French settlers set the tone for many who followed.

The British gradually took over Wisconsin during the French and Indian War, taking control of Green Bay in 1761 and gaining control of all of Wisconsin in 1763. Like the French, the British were interested in little but the fur trade. The first permanent settlers, mostly French Canadians, some Anglo-New Englanders and a few African American freedmen, arrived in Wisconsin while it was under British control. Charles Michel de Langlade is generally recognized as the first settler, establishing a trading post at Green Bay in 1745, and moving there permanently in 1764.