This is a list of municipal authorities in Juniata County, Pennsylvania.
| Municipal Authority | Function | City | External link |
|---|---|---|---|
| Juniata County Industrial Development Authority | business improvement district | Mifflintown, Pennsylvania | |
| McAlisterville Area Joint Authority | sewerage and water supply | McAlisterville, Pennsylvania | |
| Mifflintown Municipal Authority | water supply | Mifflintown, Pennsylvania | |
| Port Royal Municipal Authority | sewerage and water supply | Port Royal, Pennsylvania | |
| Richfield Area Joint Authority | water supply | Richfield, Pennsylvania | |
| Thompsontown Municipal Authority | sewerage and water supply | Thompsontown, Pennsylvania | |
| Twin Boroughs Sanitary Authority | sewage treatment | Mifflin, Pennsylvania |