Leonardo Da Vinci’s Lady with an Ermine is an Italian portrait painting from 1490, painted in oil on walnut panel. It is one of only four portraits of women by the artist, the others being the La Belle Ferronnière, Ginevra de' Benci and the Mona Lisa. The portrait's subject, Cecilia Gallerani, was the mistress of Ludovico Sforza, Duke of Milan, in whose service Leonardo was at that time. Considered one of Poland's national treasures, the painting is currently housed at the Czartoryski Museum in Kraków.