Duncannon Borough Hall is located at 428 High Street, Duncannon PA 17020; phone: 717-834-4311.
Duncannon Borough is located on the western bank of the Susquehanna River. The original borough was located on a tract of land warranted by John Brown in 1762. A part of it was bought in 1792 by Christian Miller who laid out lots and named the town Petersburg, which was incorporated in 1844.
The name Petersburg was later changed to Duncannon to avoid confusion as there were towns and post offices named Petersburg in Huntingdon, Somerset and Adams counties. Duncannon borough was incorporated in 1865.