Ludwig IV von Liegnitz
- Category : Notable-Famous-Royal-family
- Type : GP
- Profile : 4/6 - Opportunistic / Role Model
- Definition : Single
- Incarnation Cross : RAX Laws 1
Polish nobility, a Duke of Brzeg from 1633 (together with his brothers until 1654), of Wołów (during 1653-1654 with his brothers) and of Legnica from 1653 (until 1654 with his brothers, after this alone). He was the fifth but second surviving son of John Christian, Duke of Brzeg-Legnica-Wołów-Oława, by his first wife, Dorothea Sybille, daughter of John George, Elector of Brandenburg.
In Brzeg on 8 May 1649, Louis IV married Anna Sophie (Harzgerode, 29 September 1628 - Prochowice, 10 February 1666), daughter of John Albert II, Duke of Mecklenburg-Güstrow by his third wife, Eleonore Maria of Anhalt-Bernburg, first cousin of Louis IV's father John Christian; thus, the spouses were second cousins. They had one son, Christian Albert (7 November 1651 - 20 January 1652).
After his death (in Legnica on 24 November 1663) without surviving issue, Louis IV was succeeded by his brothers George III and Christian. George III died soon thereafter, and Christian reunited all their lands under his rule.