| Sergei Georgievich | |
| Succession: | Duke of Leuchtenberg |
| Reign: | 26 September 1942 – 7 January 1974 |
| Predecessor: | Alexander Georgievich, 7th Duke of Leuchtenberg |
| House: | Beauharnais |
| Father: | George Maximilianovich, 6th Duke of Leuchtenberg |
| Mother: | Princess Anastasia of Montenegro |
| Birth Date: | 4 July 1890 |
| Birth Place: | Peterhof, Russian Empire |
| Death Place: | Rome, Italy |
Prince Sergei Georgievich Romanowsky, 8th Duke of Leuchtenberg (4 July 1890 – 7 January 1974) was the son of Prince George Maximilianovich Romanowsky, 6th Duke of Leuchtenberg and his second wife Princess Anastasia of Montenegro. He succeeded his half-brother Alexander Georgievich as Duke of Leuchtenberg from 1942 until his death.
Prince Sergei was born on 4 July 1890 in Peterhof, Russian Empire to George Maximilianovich, 6th Duke of Leuchtenberg and Princess Anastasia of Montenegro. Sergei was styled His Serene Highness from birth until 1899 when he was granted the style of His Highness. George's first wife, Duchess Therese Petrovna of Oldenburg, died in 1883, leaving a young son. Sergei's father remarried six years later, when he caught the attention of Princess Anastasia of Montenegro at her sister Milica's wedding. George and Anastasia soon married and produced two children, Sergei and Elena. Anastasia divorced her husband in 1906 in order to marry Grand Duke Nicholas Nikolaevich of Russia.[1] [2]
Sergei introduced Alexander Andreyevich Svechin to his step-father Grand Duke Nicholas Nikolaevich, who was known for his religiosity and interest in mysticism.[3] Grand Duke Nicholas died in 1929, and Sergei attended his funeral along with his sister Princess Elena.[4]
Sergei died 16 December 1974 in Rome and was buried in the non-Catholic cemetery for foreigners in Testaccio, Rome, Italy. He was the last Duke of Leuchtenberg (now living descendants of the Duke of Leuchtenberg are descended from a morganatic marriage, which is why they lost their dynastic status of the members of the Russian Imperial House and the right to the Bavarian ducal title and style).
He received the following honours:[5]