Mullen is a village in Hooker County, Nebraska, United States. The population was 491 at the 2000 census. It is the county seat of Hooker County.
Mullen is located at 42°2′33″N 101°2′44″W / 42.0425°N 101.04556°W / 42.0425; -101.04556 (42.042480, -101.045611).
According to the United States Census Bureau, the village has a total area of 0.4 square miles (1.0 km²), all of it land. Mullen was named after Charles D. Mullen of Lincoln. At that time Mr. Mullen was Chief Clerk for Mr. D.E. Thompson, Division Superintendent of the CB&Q Railroad.