Tomie de Paola may be best known for Strega Nona and Big Anthony, but he also has written several wonderful picture books about saints. One of our favorites is The Holy Twins, about Ss. Benedict and Scholastica. St. Scholastica has a prominence in the retelling that she doesn't often get. It is a wonderful story of the natural and supernatural love of a brother and a sister.
Our four year old loves the book. After we read it a few times he started adding Ss. Benedict and Scholastica to the little litany of the saints we pray at the beginning of each meal.
De Paola also has a nice book about St. Francis. And his retelling of the medieval legend, the Juggler of Our Lady, called The Clown of God, is quite moving. de Paola is able to make the rural Italian village come to life.