Frederick VI (30 July 1769 – 2 April 1829) reigned as Landgrave of Hesse-Homburg from 1820 until his death in 1829.

Born in Homburg, Hesse, on 30 July 1769, Friedrich Joseph Ludwig Carl August^[2] was the eldest son of the incumbent Landgrave of Hesse-Homburg, Frederick V, and his wife Caroline of Hesse-Darmstadt, the eldest child of the then Landgrave of Hesse-Darmstadt, Louis IX.

Frederick was appointed a captain of the Russian cavalry in 1783 and was made an Austrian general during the Great French War.^[2] For his services in that conflict, he was created a Commander of the Austrian Military Order of Maria Theresa.^[2]

Despite the vocal objections of her mother, Charlotte of Mecklenburg-Strelitz, Frederick married Princess Elizabeth of the United Kingdom, the third daughter of King George III, in the Queen's House in the Mall (now integrated into Buckingham Palace) on 7 April 1818.^[3] It was no love match: Elizabeth longed to be free from her domineering mother at any cost, while Frederick needed her sizeable dowry to improve the Landgraviate's strained finances.^[4] As Elizabeth was over the age of 48 at the time of their marriage, this union produced no offspring.

Landgrave Frederick V died on 20 January 1820; Frederick succeeded him as monarch of the 221 km² (85 sq mi) principality.^[5] The new Landgrave struggled to repay his father's exorbitant debts.^[6] Nine years into his reign, the Landgrave died of complications from a pre-existing leg wound.^[7] He was succeeded by his brother, Louis William.

• Fraser, Flora: Princesses: The Six Daughters of George III, John Murray, 2004, London, ISBN 0-7195-6108-6