Louis V, Landgrave of Hesse Darmstadt

Louis V of Hesse-Darmstadt (German: Ludwig; 24 September 1577 – 27 July 1626) was the Landgrave of Hesse-Darmstadt from 1596 to 1626.

He was born on 24 September 1577 as the son of George I, Landgrave of Hesse-Darmstadt and Magdalene of Lippe.

In 1604 he inherited a part of Hessen-Marburg after the death of Louis IV of Hesse-Marburg who was childless. The other half went to Maurice of Hesse-Kassel (or Hesse-Cassel), but since Maurice was a Calvinist, Ludwig claimed a right on the whole of Hesse-Marburg. Lutheran professors of the University of Marburg who refused to convert to Calvinism founded in 1607 the University of Gießen which was named Ludoviciana.

This led to a conflict during the Thirty Years' War, between Louis V, who stood on the side of the Emperor, and Maurice, who was on the side of the Protestants. Hesse-Darmstadt suffered severely from the ravages from the Swedes during the conflict.

The Landgrave died in 1626 and he was succeeded by George II, Landgrave of Hesse-Darmstadt.

In 1722, Johann Georg Liebknecht, an astronomer at the University of Gießen, named a star, which he thought was a planet, Sidus Ludoviciana after Ludwig V.