| Archduke Sigismund of Austria | |
| Birth Name: | Sigismund Leopold Maria Rainer Ambrosius Valentin |
| Birth Date: | 7 January 1826 |
| Birth Place: | Milan |
| Death Date: | 19 December 1891 |
| Death Place: | Vienna |
| House: | Habsburg-Lorraine |
| Father: | Archduke Rainer Joseph of Austria |
| Mother: | Princess Elisabeth of Savoy |
Archduke Sigismund of Austria (Sigismund Leopold Maria Rainer Ambrosius Valentin) (Milan, 7 January 1826 – Vienna, 15 December 1891), was an Archduke of Austria.
He was the third son of Archduke Rainer Joseph of Austria, Viceroy of the Kingdom of Lombardy–Venetia and Princess Elisabeth of Savoy.In Imperial-Austrian military services, Sigismund reached the rank of Fieldmarshal-Lieutenant and was owner of the Infantry Regiment No. 45. He participated at the head of a brigade in the Battles of Santa Lucia, Pastrengo and Novara[1] (1848-1849). In 1852 he was made a Knight of the Order of the Golden Fleece by Emperor Franz Joseph.[2]
In 1859 Sigismund came into the possession of Gmünd Castle. As a passionate botanist and dendrologist, he had an orchid and palm house as well as a spacious landscape park constructed.[3]
Sigismund contracted a viral disease then called influenza (see 1889–1890 pandemic) in Vienna on December 15th 1891, died from pneumonia unmarried and childless four days later[4] and was buried in his own mausoleum in the Gmünd cemetery.