Louis, Prince of Hesse and by Rhine (Ludwig Hermann Alexander Chlodwig, 20 November 1908 – 30 May 1968) was the youngest son of Ernest Louis, Grand Duke of Hesse by his second wife Eleonore of Solms-Hohensolms-Lich.
He succeeded his brother Georg Donatus as the titular Grand Duke of Hesse after his death. He married the Hon. Margaret Campbell-Geddes (1913–1997) daughter of Auckland Campbell-Geddes, 1st Baron Geddes in 1937, on the day after the Sabena OO-AUB Ostend crash. They had no issue, although after the death of his older brother, he adopted his niece, Johanna (b. 1936) but the little girl died in 1939.
In 1960 Prince Louis adopted his distant cousin Moritz, Landgrave of Hesse. With the death of Prince Louis in Frankfurt he was succeeded by Moritz's father Philipp, Landgrave of Hesse as head of the house.
Descent before Gilbert I, Count of the Maasgau is taken from and may be inaccurate.