According to the Ross Township website (see link below), the township was formed in 1809 from Pine Township and named for a prominent Pittsburgh attorney, James Ross. Ross' borders changed over the course of time when Allegheny City was formed to the south and Shaler Township was formed to the east. Both took place before the turn of the 20th Century. In 1905 the Borough of West View was formed in the southwest corner of Ross Township. Since then, the borders have remained relatively unchanged.
There were 13,892 households out of which 24.3% had children under the age of 18 living with them, 53.4% were married couples living together, 7.4% had a female householder with no husband present, and 36.6% were non-families. 31.8% of all households were made up of individuals and 13.5% had someone living alone who was 65 years of age or older. The average household size was 2.26 and the average family size was 2.89.
In the township the population was spread out with 19.4% under the age of 18, 5.9% from 18 to 24, 28.6% from 25 to 44, 25.0% from 45 to 64, and 21.1% who were 65 years of age or older. The median age was 43 years. For every 100 females there were 87.3 males. For every 100 females age 18 and over, there were 83.0 males.
The median income for a household in the township was $46,542, and the median income for a family was $57,917. Males had a median income of $41,736 versus $31,304 for females. The per capita income for the township was $25,883. About 2.2% of families and 4.2% of the population were below the poverty line, including 2.3% of those under age 18 and 7.8% of those age 65 or over.