Ontario is the largest city in Malheur County, Oregon, United States. It lies along the Snake River at the Idaho border. The population was 11,366 at the 2010 census. The city is the largest community in the region of far eastern Oregon, also known as the Western Treasure Valley.
Ontario is located at an elevation of 2,150 feet (660 m) above sea level.
According to the United States Census Bureau, the city has a total area of 5.17 square miles (13.39 km), all of it land.
As of the census of 2010, there were 11,366 people, 4,275 households, and 2,678 families residing in the city. The population density was 2,198.5 inhabitants per square mile (848.8/km). There were 4,620 housing units at an average density of 893.6 per square mile (345.0/km). The racial makeup of the city was 69.5% White, 0.7% African American, 1.3% Native American, 2.2% Asian, 0.1% Pacific Islander, 22.6% from other races, and 3.5% from two or more races. Hispanic or Latino of any race were 41.3% of the population.
There were 4,275 households of which 35.4% had children under the age of 18 living with them, 41.3% were married couples living together, 16.0% had a female householder with no husband present, 5.3% had a male householder with no wife present, and 37.4% were non-families. 30.9% of all households were made up of individuals and 15.3% had someone living alone who was 65 years of age or older. The average household size was 2.60 and the average family size was 3.28.
The median age in the city was 32.1 years. 28.9% of residents were under the age of 18; 12.3% were between the ages of 18 and 24; 23% were from 25 to 44; 21% were from 45 to 64; and 14.9% were 65 years of age or older. The gender makeup of the city was 47.3% male and 52.7% female.
As of the census of 2000, there were 10,985 people, 4,084 households, and 2,634 families residing in the city. The population density was 2,459.3 people per square mile (948.8/km²). There were 4,436 housing units at an average density of 993.1 per square mile (383.2/km²). The racial makeup of the city was 69.27% White, 0.55% African American, 2.69% Asian, 0.88% Native American, 0.15% Pacific Islander, 23.09% from other races, and 3.39% from two or more races. Hispanic or Latino of any race were 32.05% of the population.
There were 4,084 households out of which 35.6% had children under the age of 18 living with them, 47.4% were married couples living together, 13.1% had a female householder with no husband present, and 35.5% were non-families. 30.4% of all households were made up of individuals and 15.4% had someone living alone who was 65 years of age or older. The average household size was 2.63 and the average family size was 3.30.
In the city, the population was spread out with 30.5% under the age of 18, 11.5% from 18 to 24, 24.0% from 25 to 44, 18.6% from 45 to 64, and 15.4% who were 65 years of age or older. The median age was 31 years. For every 100 females, there were 89.7 males. For every 100 females age 18 and over, there were 85.2 males.
The median income for a household in the city was $29,173, and the median income for a family was $35,625. Males had a median income of $29,775 versus $21,967 for females. The per capita income for the city was $14,683. About 16.4% of families and 20.8% of the population were below the poverty line, including 29.0% of those under age 18 and 14.3% of those age 65 or over.