[1] Leopold Louis was born in Lauterecken in 1625 as the youngest son of George Gustavus, Count Palatine of Veldenz, from his second marriage to Maria Elizabeth of Palatinate-Zweibrücken (7 November 1581 – 18 August 1637), daughter of Duke John I.
After his father's death in 1634, he succeeded him, as his elder brothers had already died.
Leopold Louis died in Strasbourg in 1694 as a poor man and was buried in Lützelstein (now called La Petite-Pierre, in France).
As he had no surviving sons, the ruins of Veldenz were inherited by the Palatinate-Kleeburg line, the head of which was Charles XI, king of Sweden, in conflict with the nearer Electorate of Palatinate.
Leopold Louis married Agathe Christine, the youngest daughter of Count Philip Wolfgang of Hanau-Lichtenberg, on 4 Jul 1648 and had the following children: