Lady with an Ermine is a painting by Leonardo da Vinci from around 1489–1490. The subject of the portrait is Cecilia Gallerani, and painted at a time when she was the mistress of Ludovico Sforza, Duke of Milan, and Leonardo was in the service of the Duke. The painting is one of only four portraits of women painted by Leonardo, the others being the Mona Lisa, the portrait of Ginevra de' Benci, and La belle ferronnière. It is currently being displayed at Wawel Royal Castle whilst renovations are being carried out at the painting's home, Czartoryski Museum, Kraków, Poland.

The small portrait generally called The Lady with the Ermine was painted in oils on wooden panel. At the time of its painting, the medium of oil paint was relatively new to Italy, having been introduced in the 1470s.

The subject has been identified with reasonable certainty as Cecilia Gallerani, who was the mistress of Leonardo's employer, Ludovico Sforza.[2]

Cecilia Gallerani was a member of a large family that was neither wealthy nor noble. Her father served for a time at the Duke's court. At the time her portrait was painted, she was about 16 years old and was renowned for her beauty, her scholarship, and her poetry. She was betrothed at the approximate age of 10 years to a young nobleman of the house of Visconti, but the marriage was called off. Cecilia became the mistress of the Duke and bore him a son, but he chose to marry a woman from a nobler family, Beatrice d'Este.[3]

There are several interpretations of the significance of the ermine in her portrait. The ermine, a stoat in its winter coat, was a traditional symbol of purity because it was believed an ermine would face death rather than soil its white coat.[5] In his old age, Leonardo compiled a bestiary in which he recorded:

MODERATION The ermine out of moderation never eats but once a day, and it would rather let itself be captured by hunters than take refuge in a dirty lair, in order not to stain its purity.[6]

He repeats this idea in another note, "Moderation curbs all the vices. The ermine prefers to die rather than soil itself."[7] Ermines were kept as pets by the aristocracy and their white pelts were used to line or trim aristocratic garments. For Ludovico il Moro, the ermine had a further personal significance in that he had been in the Order of the Ermine in 1488 and used it as a personal emblem.[8] The association of the ermine with Cecilia Gallerani could have been intended to refer both to her purity and to make an association with her lover. Alternatively, the ermine could be a pun on her name because the Ancient Greek term for ermine, or other weasel-like species of animals, is galê (γαλῆ) or galeê (γαλέη).[9] This would be in keeping with Leonardo's placement of a juniper bush behind the figure in his portrait of Ginevra de Benci in reference to her name. Given that Gallerani gave birth to a son acknowledged by Lodovico in May 1491, and the association of weasels and pregnancy in Italian Renaissance culture, it also is possible the animal was a symbol of Cecilia's pregnancy.[10] In addition, it has been speculated that the animal in the painting appears not to be an ermine,[11] but a white ferret, a colour favoured in the Middle Ages because of the ease of seeing the white animal in thick undergrowth.

As in many of Leonardo's paintings, the composition comprises a pyramidic spiral and the sitter is caught in the motion of turning to her left, reflecting Leonardo's lifelong preoccupation with the dynamics of movement. The three-quarter profile portrait was one of his many innovations. Il Moro's court poet, Bernardo Bellincioni, was the first to propose that Cecilia is poised as if listening to an unseen speaker.

This work in particular shows Leonardo's expertise in painting the human form. The outstretched hand of Cecilia was painted with great detail. Leonardo paints every contour of each fingernail, each wrinkle around her knuckles, and even the flexing of the tendon in her bent finger.