Gladwyne is an affluent suburban community in Montgomery County, Pennsylvania, United States along the historic Philadelphia Main Line. In 2011, Gladwyne was ranked the 7th richest zip code in the country in a study by Bloomberg BusinessWeek. The population was 4,050 at the 2000 census. As Gladwyne is neither an incorporated area nor a census-designated place, all data are for the ZIP code 19035, with which the community is coterminous.