Caroline von Holnstein (8 May 1815 in Schloss Fronberg/Schwandorf – 24 July 1859, Fronberg/Schwandorf) was a German noblewoman, best known for her appearance in the Gallery of Beauties.
Caroline Maximiliana Maria Freiin von Spiering was the fifth child of Carl Theodor Freiherr von Spiering and his wife Johanna Nepumukena (née Freiin von Enzberg). On her father's death in 1829 she began looking for a suitable husband. On 9 November 1831, aged 16, she married the 34-year-old Carl Theodor Graf Holnstein from Bayern. It was a no love-match, though it did mean that the Holnstein lands passed in the direct line to the Freiherren von Spiering. Caroline moved into the Palais Holnstein in Munich, where her husband's position opened many doors for her at court, though life among the nobility bored her. On 8 December 1833 Ludwig I of Bavaria first saw her at a court academy.
At one of many banquets she met and fell in love with the married nobleman Wilhelm Freiherrn von Künsberg, who returned her affections in secret. When Wilhelm's wife died she lived with him at her Spiering castle Schloss Fronberg, and he left the cuirassiers at her behest. Caroline's husband Carl Theodor tolerated the relationship but refused her an official separation, even going so far as to have her legitimate and illegitimate children educated together. Only Carl Theodor's death cleared Caroline's way to marry Wilhelm, which she did on 21 September 1857 at the Wallfahrtskirche auf dem Kreuzberg in Schwandorf. Her illegitimate children were legitimized during her lifetime and on 7 July 1859 they were raised to the Bavarian Freiherrenstand with the title Künsberg Freiherr von Fronberg. She died at the Schloss at Fronberg and was buried there in a sarcophagus in a room adjacent to the castle chapel.
The painting of her in the Gallery of Beauties is 71.5 cm by 58 cm. On its back is written "Caroline Gräfin Holnstein aus Bayern geborene Freyin von Spiering erblickte das Licht der Welt auf dem Gute Frohnberg in Bayern dem 8. Mai 1815. Gemalt von J. Stieler 1834" ("Caroline countess Holnstein in Bavaria née Freyin von Spiering born at dem Gute Frohnberg in Bavaria on 8 May 1815. Painted by J. Stieler 1834"). It was still in the artist's studio on 18 February 1834 and was paid for in May that year.