Markesan is a city in Green Lake County, Wisconsin, United States. The population was 1,396 at the 2000 census. The center of population of Wisconsin is located in Markesan.
Markesan is located at 43°42′21″N 88°59′18″W / 43.70583°N 88.98833°W / 43.70583; -88.98833 (43.705966, -88.988289).
According to the United States Census Bureau, the city has a total area of 2.4 square miles (6.1 km²), all land and none of the area is covered with water.