Burley is the second-largest city in Idaho's Magic Valley region after Twin Falls. Along with nearby Rupert it forms the bulk of the "Mini-Cassia" area of southern Idaho.
Burley is the principal city of the Burley, ID Micropolitan Statistical Area, which includes Cassia and Minidoka Counties.
Burley is home to the famed "Spudman" Triathlon.
As of the census of 2000, there were 9,316 people, 3,288 households, and 2,373 families residing in the city. The population density was 2,262.0 people per square mile (873.0/km²). There were 3,633 housing units at an average density of 882.1/sq mi (340.5/km²). The racial makeup of the city was 77.96% White, 0.21% African American, 1.30% Native American, 0.46% Asian, 0.08% Pacific Islander, 17.15% from other races, and 2.83% from two or more races. Hispanic or Latino of any race were 26.71% of the population.
There were 3,288 households out of which 39.5% had children under the age of 18 living with them, 55.7% were married couples living together, 12.7% had a female householder with no husband present, and 27.8% were non-families. 25.0% of all households were made up of individuals and 12.2% had someone living alone who was 65 years of age or older. The average household size was 2.75 and the average family size was 3.31.
In the city the population was spread out with 31.9% under the age of 18, 10.0% from 18 to 24, 25.5% from 25 to 44, 18.1% from 45 to 64, and 14.5% who were 65 years of age or older. The median age was 31 years. For every 100 females there were 94.8 males. For every 100 females age 18 and over, there were 90.1 males.
The median income for a household in the city was $27,981, and the median income for a family was $33,376. Males had a median income of $26,865 versus $17,304 for females. The per capita income for the city was $12,689. About 15.2% of families and 18.4% of the population were below the poverty line, including 25.1% of those under age 18 and 10.7% of those age 65 or over.