Great Bend's population was estimated to be 15,537 in the year 2006, an increase of 187, or +1.2%, over the previous six years.
As of the census of 2000, there were 15,345 people, 6,371 households, and 4,000 families residing in the city. The population density was 1,443.7 people per square mile (557.4/km²). There were 7,080 housing units at an average density of 666.1/sq mi (257.2/km²). The racial makeup of the city was 89.81% White, 1.62% African American, 0.43% Native American, 0.31% Asian, 0.01% Pacific Islander, 5.77% from other races, and 2.05% from two or more races. Hispanic or Latino of any race were 15.20% of the population.
There were 6,371 households out of which 30.4% had children under the age of 18 living with them, 51.1% were married couples living together, 8.4% had a female householder with no husband present, and 37.2% were non-families. 32.8% of all households were made up of individuals and 15.2% had someone living alone who was 65 years of age or older. The average household size was 2.35 and the average family size was 3.00.
In the city the population was spread out with 25.7% under the age of 18, 9.4% from 18 to 24, 25.4% from 25 to 44, 20.9% from 45 to 64, and 18.7% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 92.3 males. For every 100 females age 18 and over, there were 87.7 males.
The median income for a household in the city was $30,841, and the median income for a family was $38,708. Males had a median income of $29,339 versus $19,647 for females. The per capita income for the city was $17,085. About 11.5% of families and 15.2% of the population were below the poverty line, including 22.0% of those under age 18 and 9.7% of those age 65 or over.