Infanta Margarita Teresa in a Blue Dress is one of the best-known portraits by Spanish painter Diego Velázquez. Executed in oil on canvas, it measures 127 cm high by 107 cm wide and was one of Velázquez's last paintings, produced in 1659, a year before his death. It shows Margaret Theresa of Spain who also appears in the artist's Las Meninas. Currently, the painting is in the Kunsthistorisches Museum.