The population was 5,217 at the 2000 census.
Benner Township is bordered by Spring Township to the northeast, College Township to the south, Patton Township to the southwest and Union Township to the northwest.
There were 1,324 households out of which 28.2% had children under the age of 18 living with them, 60.9% were married couples living together, 6.3% had a female householder with no husband present, and 29.6% were non-families. 23.9% of all households were made up of individuals and 7.2% had someone living alone who was 65 years of age or older. The average household size was 2.42 and the average family size was 2.89.
In the township the population was spread out with 13.5% under the age of 18, 9.7% from 18 to 24, 44.7% from 25 to 44, 24.3% from 45 to 64, and 7.9% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 222.0 males. For every 100 females age 18 and over, there were 252.2 males.
The median income for a household in the township was $42,083, and the median income for a family was $47,800. Males had a median income of $30,033 versus $23,979 for females. The per capita income for the township was $17,665. About 0.9% of families and 2.2% of the population were below the poverty line, including 1.3% of those under age 18 and none of those age 65 or over.
Board of Supervisors: David C. Breon (Chairman); James Swartzell (Vice Chairman); John Elnitski, Jr.
Board of Auditors: Thomas Strouse (Chairman); Rory Spangler (Vice Chairman)
Tax Collector: Janet Houser (real estate taxes)
Constable: James Millander