The Second Mrs. Giaconda, later The Second Mrs. Gioconda,is a historical novel for children by E. L. Konigsburg. Set primarily in Milan, Italy, it features Leonardo da Vinci, his servant Salai, and duchess Beatrice d'Este. Through the experiences of Salai narrated in third person, it explores the background of da Vinci's Mona Lisa. The book was published by Atheneum in 1975, manufactured by Halliday Lithograph Corporation with ten black-and-white museum plates of da Vinci paintings and drawings, of which several figure in the story.