Lady with an Ermine is a painting by Leonardo da Vinci, from around 1489–1490. The subject of the portrait is identified as Cecilia Gallerani, and was probably painted at a time when she was the mistress of Lodovico Sforza, Duke of Milan and Leonardo was in the service of the Duke.
The painting is one of only four female portraits painted by Leonardo, the others being the Mona Lisa, the portrait of Ginevra de' Benci and La Belle Ferronière. It is displayed by the Czartoryski Museum, Kraków, Poland and is cited in the museum's guide as the first truly modern portrait. When exhibited in Museum of Fine Arts in Huston, it was described as "signal[ling] a breakthrough in the art of psychological portraiture".