Jansen is a village in Jefferson County, Nebraska, United States. The population was 143 at the 2000 census. The village was named after local rancher and politician Peter Jansen.
Jansen is located at 40°11′9″N 97°4′58″W / 40.18583°N 97.08278°W / 40.18583; -97.08278 (40.185711, -97.082704).
According to the United States Census Bureau, the village has a total area of 0.2 square miles (0.6 km²), all of it land.