Sturgeon Bay is a city located in Door County, Wisconsin, within the United States, serving as the county seat. Situated at the natural end of Sturgeon Bay on the Door Peninsula, it holds the distinction of being the most populous city in this popular Upper Midwest vacation destination. The community lies at the bottom of the bay, surrounded by maritime activity and scenic landscapes that define its geographic character.

The area was originally inhabited by the Ho-Chunk and Menominee peoples, who referred to the location as Namāēw-Wīhkit, meaning bay of the sturgeon. After the Menominee ceded the territory in the 1831 Treaty of Washington, white settlement began. The community was first recorded as Graham in 1855 before being organized as the town of Ottumba in 1857. It reverted to Graham briefly before changing its name to Sturgeon Bay in 1860, incorporating as a village in 1874 and a city in 1883.

The city is locally known for the Sturgeon Bay Bridge at Michigan Street, which opened in 1931 and was once the second bridge across the bay. Stevens Hill, a populated place northeast of downtown, contains the city's highest elevation within Big Hill Park. The Sturgeon Bay Ship Canal crosses the remainder of the peninsula, facilitating heavy maritime development that led to the establishment of two shipyards, one of which remains operational today.

Cultural attractions include the Sturgeon Bay Cinema 6 and the Third Avenue Playhouse, a professional regional theatre. The town hosts the annual Steel Bridge Songfest, featuring nationally known musicians such as Jackson Browne and Jane Wiedlin. The city owns twenty parks totaling 121.7 acres, with Sunset Park being the largest. The Ice Age Trail diverges from the Ahnapee Trail to pass through the city limits for five miles before reaching its northern terminus at Potawatomi State Park.

The population was 9,646 as of the 2020 census. The community is served by Sturgeon Bay High School and a satellite campus of Northeast Wisconsin Technical College. Transportation access includes Door County Cherryland Airport and Austin Straubel International Airport in Green Bay. Major highways WIS 42 and WIS 57 connect the city to Green Bay, Milwaukee, and other regional destinations. Sturgeon Bay experiences a humid continental climate.