As of the census of 2000, there were 50,792 people, 20,779 households, and 12,799 families residing in the city. The population density was 3,652.4 people per square mile (1,409.8/km²). There were 21,762 housing units at an average density of 1,564.9/sq mi (604.1/km²). The racial makeup of the city was 87.63% White, 0.86% Black or African American, 0.48% Native American, 6.48% Asian (with many being of Hmong descent), 0.04% Pacific Islander, 2.85% from other races, and 1.68% from two or more races. 5.97% of the population were Hispanic or Latino of any race. Many of the residents have German ancestry.
There were 20,779 households out of which 29.7% had children under the age of 18 living with them, 48.2% were married couples living together, 9.4% had a female householder with no husband present, and 38.4% were non-families. 32.2% of all households were made up of individuals and 12.6% had someone living alone who was 65 years of age or older. The average household size was 2.39 and the average family size was 3.05.
In the city the population was spread out with 25.6% under the age of 18, 9.2% from 18 to 24, 30.0% from 25 to 44, 19.4% from 45 to 64, and 15.8% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 96.0 males. For every 100 females age 18 and over, there were 93.7 males.
The median income for a household in the city was $40,066, and the median income for a family was $47,718. Males had a median income of $35,242 versus $24,690 for females. The per capita income for the city was $19,270. About 6.2% of families and 8.3% of the population were below the poverty line, including 11.8% of those under age 18 and 7.0% of those age 65 or over.
Sheboygan is served by the Sheboygan County Memorial Airport, which is located several miles from the city.
Interstate 43 is the primary north-south transportation route into Sheboygan, and forms the west boundary of the city. U.S. Route 141 was the primary north-south route into Sheboygan before Interstate 43 was built, and its former route is a major north-south route through the center of the city that is referred to as Calumet Drive coming into the city from the north, and South Business Drive from the south; between Superior and Georgia Avenues, the highway is known as 14th Street. Four-lane Highway 23 is the primary west route into the city. Other state highways in the city include Highway 42, Highway 28, which both run mostly along the former inner-city routing of U.S. 141. Secondary county highways include County LS to the north; Counties J, O, PP, and EE to the west; and County KK to the south. Sheboygan Transit System provides bus service throughout the city.
Since 1995 Sheboygan has been the site of eight- and twenty-foot tall rocket launches for a local high school program called Rockets for Schools. Sheboygan is also the site of a proposed new spaceport called Spaceport Sheboygan.
Sheboygan is bounded on the east by Lake Michigan. There are no active ports in the city. The current site of Blue Harbor Resort sits on a peninsula between the lake and the Sheboygan River's last bend that was formerly used by the C. Reiss Coal Company (now a Koch Industries division) as their headquarters and base of operations, where ships would load and unload coal along the peninsula. The company's former headquarters building on North 8th Street is being converted into a condominium development.
The Sheboygan River also passes through the city, but waterfalls upstream in Sheboygan Falls prevent navigation, while tall-masted boats are confined to the river downstream of the Pennsylvania Avenue bridge. Commercial charter fishing boats dock near the mouth of the river.
Water service is provided by the Sheboygan Water Utility, which pumps water into the city via intake pipes which are 1.25 miles out from the Lake Michigan shore north of North Point. The utility also provides water service to portions of the Towns of Sheboygan and Wilson, Kohler, and Sheboygan Falls.