|• Total||39.2 sq mi (101.4 km2)|
|• Land||35.1 sq mi (91.0 km2)|
|• Water||4.0 sq mi (10.4 km2)|
|Elevation||39 ft (12 m)|
|• Density||684/sq mi (264.2/km2)|
|Time zone||UTC-5 (Eastern (EST))|
|• Summer (DST)||UTC-4 (EDT)|
33556 & 33558
|GNIS feature ID||0300080|
Keystone is an unincorporated census-designated place in Hillsborough County, Florida, United States. The population was 24,039 at the 2010 census, up from 14,627 at the 2000 census. The ZIP Codes encompassing the CDP area are 33556 and 33558.
Keystone is located in the northwest corner of Hillsborough County at  It is bordered to the east by Cheval and Northdale, to the southeast by Citrus Park, and to the south by Westchase, all in Hillsborough County. To the west, Keystone is bordered by East Lake in Pinellas County, and to the north the CDP is bordered by Trinity and Odessa in Pasco County. Keystone is 22 miles (35 km) northwest of downtown Tampa. According to the United States Census Bureau, the CDP has a total area of 39.2 square miles (101.4 km2), of which 35.1 square miles (91.0 km2) are land and 4.0 square miles (10.4 km2), or 10.29%, are water.(28.127550, -82.589117).
As of the census of 2000, there were 14,627 people, 5,160 households, and 4,380 families residing in the community. The population density was 405.4 people per square mile (156.5/km²). There were 5,709 housing units at an average density of 158.2/sq mi (61.1/km²). The racial makeup of the community was 91.30% White, 3.50% African American, 0.34% Native American, 2.45% Asian, 0.05% Pacific Islander, 0.94% from other races, and 1.42% from two or more races. Hispanic or Latino of any race were 8.48% of the population.
There were 5,160 households out of which 41.7% had children under the age of 18 living with them, 78.2% were married couples living together, 4.7% had a female householder with no husband present, and 15.1% were non-families. 11.1% of all households were made up of individuals and 3.0% had someone living alone who was 65 years of age or older. The average household size was 2.83 and the average family size was 3.08.
In the community the population was spread out with 27.2% under the age of 18, 4.8% from 18 to 24, 33.3% from 25 to 44, 27.1% from 45 to 64, and 7.7% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 100.4 males. For every 100 females age 18 and over, there were 97.9 males.
The median income for a household in the community was $80,677, and the median income for a family was $84,592 (these figures had risen to $106,549 and $112,119 respectively as of a 2007 estimate). Males had a median income of $55,905 versus $37,190 for females. The per capita income for the community was $35,136. About 1.4% of families and 2.4% of the population were below the poverty line, including 2.7% of those under age 18 and 5.4% of those age 65 or over.
Keystone is served by Hillsborough County Public School through the following:
- Bryant Elementary School
- Hammond Elementary School
- Northwest Elementary School
- McKitrick Elementary School
- Farnell Middle School
- Martinez Middle School
- Steinbrenner High School
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.
- "US Board on Geographic Names". United States Geological Survey. 2007-10-25. Retrieved 2008-01-31.
- "Geographic Identifiers: 2010 Demographic Profile Data (G001): Keystone CDP, Florida". American Factfinder. U.S. Census Bureau. Retrieved May 3, 2017.
- Zip Codes for Keystone, Hillsborough County, Florida. Retrieved 2013-12-27.
- "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. 2011-02-12. Retrieved 2011-04-23.
- "CENSUS OF POPULATION AND HOUSING (1790-2000)". U.S. Census Bureau. Retrieved 2010-07-17.