Altar of St. Luke also known as the Bandinelli altar because it was entrusted to the patronage of this family. On the altar is Girolamo del Pacchia's painting of the Madonna Enthroned with the Infant Jesus, St. Luke and St. Benedict dressed in the manner of the Olivetans. Attributed to Girolamo del Pacchia and painted in the sixteenth century, following the decoration of the Oratory of San Bernardino alongside artists such as Sodoma and Beccafumi, to whom it is similar in style, in the wake of Raphael's fascination with stylistic novelties in Rome. The prized altarpiece is framed in an altar of Baroque workmanship, mirroring that in front of the crucifix.
To the right of the altar of St. Luke is walled a plaque, the oldest one in the church, which reads "+ NOBILIS PUER ATQUE TENELLUS JACET HIC BANDINELLUS JUBENTE DOMINO IOANNE AVO ANNO MCCL OCTAVO" or "Here lies Bandinello noble and tender child by the will of his grandfather Signor Giovanni year 1250 eighth year of his life.
Below the epigraph is depicted the seal of the Bandinelli family, owners of the chapel, the golden coat of arms with the roundel in the upper left corner.