Mantua (/ˈmænəweɪ/ MAN-ə-way) is a town on the eastern edge Box Elder County, Utah, United States. The population of the town was 687 at the 2010 census.
Mantua lies at the head of Box Elder Canyon on the northern, western, and southern sides of the Mantua Reservoir.
According to the United States Census Bureau, the town has a total area of 5.6 square miles (15 km), of which 4.9 square miles (13 km) are land and 0.7 square miles (1.8 km) (13.21%) is water.
As of the census of 2000, there were 791 people, 218 households, and 189 families residing in the town. The population density was 162.5 people per square mile (62.7/km²). There were 231 housing units at an average density of 47.5 per square mile (18.3/km²). The racial makeup of the town was 96.33% White, 0.63% African American, 0.51% Native American, 0.25% Asian, 0.51% from other races, and 1.77% from two or more races. Hispanic or Latino of any race were 0.88% of the population.
There were 218 households out of which 52.8% had children under the age of 18 living with them, 79.4% were married couples living together, 5.0% had a female householder with no husband present, and 13.3% were non-families. 12.4% of all households were made up of individuals and 5.5% had someone living alone who was 65 years of age or older. The average household size was 3.63 and the average family size was 4.01.
In the town, the population was spread out with 38.2% under the age of 18, 10.1% from 18 to 24, 23.3% from 25 to 44, 20.1% from 45 to 64, and 8.3% who were 65 years of age or older. The median age was 30 years. For every 100 females, there were 108.7 males. For every 100 females age 18 and over, there were 103.8 males.
The median income for a household in the town was $60,234, and the median income for a family was $61,964. Males had a median income of $42,100 versus $26,875 for females. The per capita income for the town was $17,798. About 0.5% of families and 1.7% of the population were below the poverty line, including 2.1% of those under age 18 and 3.4% of those age 65 or over.