As of the census of 2000, there were 34,053 people, 14,235 households, and 8,811 families residing in the city. The population density was 2,018.8 people per square mile (779.4/km²). There were 15,007 housing units at an average density of 889.7/sq mi (343.5/km²). The racial makeup of the city was 93.13% White, 0.59% Black or African American, 0.55% Native American, 3.77% Asian, 0.07% Pacific Islander, 0.90% from other races, and 0.99% from two or more races. 2.52% of the population were Hispanic or Latino of any race.
There were 14,235 households out of which 28.6% had children under the age of 18 living with them, 49.0% were married couples living together, 9.1% had a female householder with no husband present, and 38.1% were non-families. 32.5% of all households were made up of individuals and 14.6% had someone living alone who was 65 years of age or older. The average household size was 2.32 and the average family size was 2.96.
In the city the population was spread out with 24.1% under the age of 18, 8.2% from 18 to 24, 27.9% from 25 to 44, 21.4% from 45 to 64, and 18.4% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 93.9 males. For every 100 females age 18 and over, there were 90.9 males.
The median income for a household in the city was $38,203, and the median income for a family was $47,635. Males had a median income of $35,176 versus $22,918 for females. The per capita income for the city was $19,954. About 5.0% of families and 7.9% of the population were below the poverty line, including 11.7% of those under age 18 and 7.5% of those age 65 or over.
Public Transportation in the city been provided by Maritime Metro Transit since 1978, covering both Manitowoc and Two Rivers, Wisconsin. MMT currently has a fleet of 12 buses serving over 40 stops on 8 routes.
Commercial, charter, and cargo air transportation is available through the Manitowoc County Airport.
Manitowoc is the western port for the S.S. Badger ferry, that crosses Lake Michigan to Ludington, Michigan. The ferry ride is part of the route of U.S. Route 10.
The Manitowoc Mariners Trail is a 5.5-mile paved recreational trail running along the shore of Lake Michigan between the cities of Manitowoc and Two Rivers, Wisconsin.