The Treaty of Vossem was signed on 6 June 1673, between Frederick William, Elector Brandenburg and Louis XIV of France; England, then a French ally against the Dutch, was included as a party to the terms but not a signatory. It was ratified by both parties on 20 July.

Frederick William was Elector of Brandenburg and Duke of Prussia, thus ruler of Brandenburg-Prussia, from 1640 until his death in 1688. A member of the House of Hohenzollern, he is popularly known as "the Great Elector" because of his military and political achievements. Frederick William was a staunch pillar of the Calvinist faith, associated with the rising commercial class. He saw the importance of trade and promoted it vigorously. His shrewd domestic reforms gave Prussia a strong position in the post-Westphalian political order of Northern-Central Europe, setting Prussia up for elevation from duchy to kingdom, achieved under his son and successor.