Gladstone is an unincorporated community located within Peapack-Gladstone in Somerset County, in the U.S. state of New Jersey. The area is served as United States Postal Service ZIP Code 07934. Gladstone was named in honor of William Ewart Gladstone, who served as British Prime Minister several times between 1868 and 1894. The community is home to the Hamilton Farm Golf Club, the Stronghold Soccer Club, the United States Equestrian Team and the Gill St. Bernard's School, a private, nonsectarian, coeducational day school, serving students in pre-kindergarten through twelfth grade.