Kiel is a city in Calumet and Manitowoc counties in the U.S. state of Wisconsin.

The population was 3,738 at the 2010 census. Of this, 3,429 were in Manitowoc County, and 309 were in Calumet County. The city is located mostly within Manitowoc County, though a portion extends west into adjacent Calumet County.

It was once known as the "Wooden Shoes" Capital of Wisconsin as it held the only wooden shoes factory in Wisconsin. Today, Kiel is known as the home for Land O'Lakes, Sargento, PolarWare/Stoelting, H.G. Weber Company and HUI, among other local manufacturers.

Kiel is located at 43°54′53″N 88°1′55″W (43.914718, -88.031812), along the Sheboygan River.
According to the United States Census Bureau, the city has a total area of 2.67 square miles (6.92 km2), of which, 2.53 square miles (6.55 km2) is land and 0.14 square miles (0.36 km2) is water.

2010 census
As of the census of 2010, there were 3,738 people, 1,565 households, and 1,021 families residing in the city. The population density was 1,477.5 inhabitants per square mile (570.5 /km2). There were 1,697 housing units at an average density of 670.8 per square mile (259.0 /km2). The racial makeup of the city was 96.9% White, 0.4% African American, 0.6% Native American, 0.6% Asian, 0.7% from other races, and 0.8% from two or more races. Hispanic or Latino of any race were 2.0% of the population.
There were 1,565 households of which 33.0% had children under the age of 18 living with them, 53.4% were married couples living together, 8.1% had a female householder with no husband present, 3.8% had a male householder with no wife present, and 34.8% were non-families. 29.9% of all households were made up of individuals and 13.8% 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 2.98.
The median age in the city was 38.7 years. 26.5% of residents were under the age of 18; 5.3% were between the ages of 18 and 24; 27.6% were from 25 to 44; 25% were from 45 to 64; and 15.7% were 65 years of age or older. The gender makeup of the city was 48.0% male and 52.0% female.

Wisconsin Highway 67 run north/south at the extreme east edge of Kiel. Highways 32 and 57 run through downtown Kiel, entering the city from the north at the northwest corner of the city and enter from the east at the southeast corner of the city. Wisconsin Highway 149 originally had its western terminus in Kiel. It later was extended west to Fond du Lac. Many years later the original route from Cleveland to Kiel was decommissioned and the eastern terminus of the highway was located in Kiel. The entire route was decommissioned in the 2000s.

The Sheboygan River enters the city in the south edge of the city, runs through downtown, and exits the city in the east side of the city. The river is rarely used as a means of transportation.

There is a dam in downtown Kiel and another one several miles downstream in Millhome.
Kiel is served by the Wisconsin and Southern Railroad. Historically this line was built by the Milwaukee Road.