Gilbert is an unincorporated community in Monroe County, Pennsylvania, United States. The ZCTA for its ZIP Code, 18331, had a population of 459 at the 2000 census. It is located on U.S. Route 209 in Chestnuthill Township and Polk Township. The Pohopoco Creek runs it southward through Gilbert then westward through Beltzville Lake to the Lehigh River. Gilbert is served by the 681 exchange in Area Code 610. Students in the village area attend the Pleasant Valley School District.