Tremonton is a city in Box Elder County, Utah, United States. The population was 7,647 at the 2010 census.
Tremonton lies in the Bear River Valley in northeastern Box Elder County. The Malad River flows through the city. According to the United States Census Bureau, the city has a total area of 7.8 square miles (20.2 km), all of it land. Tremonton is located near the junction of Interstate 15 and Interstate 84. It is bordered on the north by the city of Garland, with which it is closely associated. The town of Elwood is 2 miles (3 km) to the southeast.
As of the census of 2000, there were 5,592 people, 1,698 households, and 1,397 families residing in the city. The population density was 1,066.8 people per square mile (412.0/km²). There were 1,822 housing units at an average density of 347.6 per square mile (134.3/km²). The racial makeup of the city was 91.52% White, 0.16% African American, 0.45% Native American, 1.13% Asian, 0.04% Pacific Islander, 5.22% from other races, and 1.48% from two or more races. Hispanic or Latino of any race were 9.71% of the population.
There were 1,698 households out of which 50.6% had children under the age of 18 living with them, 70.7% were married couples living together, 9.3% had a female householder with no husband present, and 17.7% were non-families. 15.4% of all households were made up of individuals and 6.9% had someone living alone who was 65 years of age or older. The average household size was 3.26 and the average family size was 3.67.
In the city, the population was spread out with 39.0% under the age of 18, 10.5% from 18 to 24, 26.7% from 25 to 44, 14.7% from 45 to 64, and 9.1% who were 65 years of age or older. The median age was 25 years. For every 100 females, there were 98.7 males. For every 100 females age 18 and over, there were 94.8 males.
The median income for a household in the city was $44,784, and the median income for a family was $49,100. Males had a median income of $36,764 versus $22,149 for females. The per capita income for the city was $15,737. About 8.3% of families and 9.9% of the population were below the poverty line, including 14.3% of those under age 18 and none of those age 65 or over.