Founded in 1800, Butler County is one of 67 counties in the state of Pennsylvania. Historically, Butler County was formed from parts of Allegheny County. The city of Butler is the county seat. With FIPS code of 19, Butler County has a population of 194,273 and area of 795 square miles (2,059 km2).
List of all cities in Butler County, PA alphabetically
| City/Town | Postal Code | Area Code |
| Annandale, PA | 16018 | 724/878 |
| 16020 | 724/878 | |
| Barkeyville, PA | 16038 | 724/878 |
| Boyers, PA | 16016 | 724/878 |
| 16017 | 724/878 | |
| 16018 | 724/878 | |
| 16020 | 724/878 | |
| Branchton, PA | 16021 | 724/878 |
| Bruin, PA | 16022 | 724/878 |
| Butler, PA | 16001 | 724/878 |
| 16002 | 724/878 | |
| 16003 | 724/878 | |
| Cabot, PA | 16023 | 724/878 |
| Callery, PA | 16024 | 724/878 |
| Chicora, PA | 16025 | 724/878 |
| Connoquenessing, PA | 16027 | 724/878 |
| Cranberry Township, PA | 16066 | 724/878 |
| East Butler, PA | 16029 | 724/878 |
| Eau Claire, PA | 16030 | 724/878 |
| Evans City, PA | 16033 | 724/878 |
| Fenelton, PA | 16034 | 724/878 |
| Forestville, PA | 16035 | 724/878 |
| Harmony, PA | 16037 | 724/878 |
| Harrisville, PA | 16038 | 724/878 |
| Herman, PA | 16039 | 724/878 |
| Hilliards, PA | 16040 | 724/878 |
| Karns City, PA | 16041 | 724/878 |
| Lyndora, PA | 16045 | 724/878 |
| Mars, PA | 16046 | 724/878 |
| Marwood, PA | 16023 | 724/878 |
| Meridian, PA | 16001 | 724/878 |
| National Agency for Check Inqu, PA | 16018 | 724/878 |
| North Washington, PA | 16048 | 724/878 |
| Office of Personnel Mgmt, PA | 16017 | 724/878 |
| Petrolia, PA | 16050 | 724/878 |
| Portersville, PA | 16051 | 724/878 |
| Prospect, PA | 16052 | 724/878 |
| Renfrew, PA | 16053 | 724/878 |
| Sarver, PA | 16055 | 724/878 |
| Saxonburg, PA | 16056 | 724/878 |
| Seven Fields, PA | 16046 | 724/878 |
| Slippery Rock, PA | 16057 | 724/878 |
| Social Security Admin, PA | 16016 | 724/878 |
| Valencia, PA | 16059 | 724/878 |
| West Sunbury, PA | 16061 | 724/878 |
| Zelienople, PA | 16063 | 724/878 |