The Pharisburg Post office was established as the Pharisburgh Post Office on April 25, 1840, but was discontinued on October 24, 1845. It was reestablished on September 7, 1848, and the name was changed to Pharisburg Post Office on March 26, 1892. The Post Office was finally discontinued on April 15, 1908. The mail service is now sent through the Marysville branch.
Pharisburg was named for Robert Phares, who in 1833 purchased 1,000 acres on Bokes Creek from Joseph Otis of New York, and Nathaniel Dunlop of Richmond, Virginia. Phares lived there until his death in 1839.