|Official name: Borough of Callery|
|Area||1.4 km2 (1 sq mi)|
|- land||1.4 km2 (1 sq mi)|
|- water||0.0 km2 (0 sq mi)|
|Density||283.5 / km2 (734.3 / sq mi)|
|- summer (DST)||EDT (UTC-4)|
|School District||Seneca Valley|
Callery is located in the northwestern corner of Adams Township in southwestern Butler County, at (40.739587, -80.037211). It is 3.7 miles (6.0 km) northwest of Mars and 2.8 miles (4.5 km) southeast of Evans City; all three boroughs are in the valley of Breakneck Creek.
As of the census of 2000, there were 444 people, 157 households, and 121 families residing in the borough. The population density was 838.1 people per square mile (323.5/km²). There were 164 housing units at an average density of 309.6 per square mile (119.5/km²). The racial makeup of the borough was 99.10% White, and 0.90% from two or more races.
There were 157 households out of which 43.3% had children under the age of 18 living with them, 62.4% were married couples living together, 11.5% had a female householder with no husband present, and 22.3% were non-families. 18.5% of all households were made up of individuals and 8.3% 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 3.25.
In the borough the population was spread out with 30.4% under the age of 18, 8.1% from 18 to 24, 32.7% from 25 to 44, 20.3% from 45 to 64, and 8.6% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 96.5 males. For every 100 females age 18 and over, there were 98.1 males.
The median income for a household in the borough was $42,308, and the median income for a family was $44,091. Males had a median income of $35,000 versus $22,679 for females. The per capita income for the borough was $16,049. About 2.3% of families and 2.5% of the population were below the poverty line, including 0.9% of those under age 18 and 5.7% of those age 65 or over.
Callery was established in 1880, with the post office opening in 1884. Most of the community was lost to a fire in 1892; however, with the area being a major rail hub, many of the structures were rebuilt. The community was incorporated into a borough in 1905.
Located along the P&W Subdivision, the borough was originally a small whistle stop on the Pittsburgh and Western Railroad. However, by the turn of the 20th century, Callery became a prosperous railroad community with the completion of the Northern Subdivision, which connected with the P&W line in Callery. The Northern Subdivision ran from the junction to the village of Ribold outside of Butler. This new connection turned Callery into a major hub for the B&O Railroad, and for the next three decades it would be called Callery Junction. By the 1930s, a new connection was completed at Eidenau which eliminated the sharp curves and grades to Ribold. Soon after, traffic on the old connection ceased, and Callery Junction was no more. Trains from the Buffalo and Pittsburgh Railroad still pass the small borough today, but the junction has been gone for almost eighty years.
- An Historical Gazetteer of Butler County, Pennsylvania, Mechling Bookbindery., 2006, ISBN 978-0-9760563-9-3.
- "Geographic Identifiers: 2010 Demographic Profile Data (G001): Callery borough, Pennsylvania". U.S. Census Bureau, American Factfinder. Retrieved March 24, 2014.
- "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. 2011-02-12. Retrieved 2011-04-23.
- "Census of Population and Housing". U.S. Census Bureau. Retrieved 11 December 2013.
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.
- "Incorporated Places and Minor Civil Divisions Datasets: Subcounty Resident Population Estimates: April 1, 2010 to July 1, 2012". Population Estimates. U.S. Census Bureau. Retrieved 11 December 2013.
- An Historical Gazetteer of Butler County, Pennsylvania, pp. 125.