Stephen Salisbury III (1835–1905), also referred to as Stephen Salisbury Jr., was an American businessman, lawyer, and politician. The son of a wealthy landowner, Salisbury helped manage the family's extensive properties and businesses in Worcester County, Massachusetts. Like his father, Salisbury served in the State Senate, was president of the Worcester National Bank, and directed the Worcester & Nashua Railroad. He was a trustee of the Worcester City Hospital and the Worcester Polytechnic Institute.

The American Antiquarian Society (AAS), located in Worcester, Massachusetts, is both a learned society and a national research library of pre-twentieth-century American history and culture. Founded in 1812, it is the oldest historical society in the United States with a national focus. Its main building, known as Antiquarian Hall, is a U.S. National Historic Landmark in recognition of this legacy. The mission of the AAS is to collect, preserve and make available for study all printed records of what is now known as the United States of America. This includes materials from the first European settlement through the year 1876.