Monroe, county, eastern Pennsylvania, U.S., bordered by New Jersey to the east (the Delaware River constituting the boundary), Blue and Kittatinny mountains to the south, Tobyhanna and Tunkhannock creeks to the west, and the Lehigh River to the northwest. Its varied topography includes the Pocono Mountains in the north and ridge-and-valley terrain in the south. Other waterways include McMichael, Brodhead, and Cherry creeks; Lake Naomi and Pocono Lake are in the Pocono Mountains. Parklands include Big Pocono, Gouldsboro, and Tobyhanna state parks and sites along the Delaware River such as the Delaware Water Gap, where the river traverses the Kittatinny Mountains. The Appalachian National Scenic Trail follows the ridgeline of Blue and Kittatinny mountains.
The county was formed in 1836 and named for James Monroe. Tourism is important to resort communities such as East Stroudsburg, Mount Pocono, and Stroudsburg, which is the county seat. Area 607 square miles (1,573 square km). Pop. (2000) 138,687; (2010) 169,842.