Philipp Franz Wilhelm Ignaz Peter, Fürst von der Leyen und zu Hohengeroldseck (1 August 1766 - 23 November 1829) was a German nobleman who briefly ruled the Principality of Leyen.
He was born at Koblenz, the son of Franz Georg Karl Anton von der Leyen und zu Hohengeroldseck and his wife Maria Anna Sophia Kämmerer von Worms, Baroness of Dalberg. His mother's brother was Karl Theodor Anton Maria von Dalberg, who later became Prince-Primate of the Confederation of the Rhine. On 26 September 1775 Philipp Franz succeeded his father as Count of Hohengeroldseck.
On the establishment of the Confederation of the Rhine on 12 July 1806, the County of Hohengeroldseck was raised to a Principality, and Philipp Franz became Fürst von der Leyen und zu Hohengeroldseck. The Confederation was dissolved in 1813 and from 30 May 1814 the Principality of Leyen was under Allied administration. By the Congress of Vienna it was given to Austria, but was sold to the Grand Duchy of Baden in 1819. Philipp Franz kept the title of Fürst (Prince), though now without a Principality. He died at the age of 63 in Köln.
On 15 May 1788 at Pommersfelden, Philipp Franz was married to Sophia Therese Walpurgis (Mainz 15 August 1772 - Paris 4 July 1810), daughter of Count Hugo Damian of Schönborn-Buchheim. They had two children: