Pier Maria Baldi (circa 1630 - November 9, 1686) was an Italian painter and architect.
Born around 1630 in Florence, Pier Maria Baldi trained under Baldassare Franceschini, known as il Volterrano. He worked along with fellow pupil Cosimo Ulivelli in Franceschini's projects, decorating rooms in the Palazzo Giraldi, now Taddei, on via de' Ginori.
In 1667 the Grand Duke Ferdinando II recommended Pier Maria to Bernini and Pietro da Cortona in Rome. From September 1668 to March 1669 he was a chamberlain to the future Cosimo III de Medici, while the latter traveled through Europe, including France, Spain, Portugal, Ireland, England, the Netherlands and Belgium. He documented painted and drawn vedute of this trip, conserved in two volumes in the Biblioteca Laurenziana of Florence. This is a fascinating collection of the skylines of European towns in the 17th century.
Among his painted figure pieces are a Madonna of the Rosary and Saint Domenic (circa 1684) for the main altar of San Domenico al Maglio (now belonging to the Scuola di Santità Militare) and a lunette frescoed with the Baptism of St Augustine in the first cloister of Santo Spirito.
He had trained as an architect under Ferdinando Tacca, and joined Tacca's team enlarging the Palazzo Medici Riccardi, which had been purchased by Gabriello Riccardi in 1659. From 1670 to 1684 Baldi designed for him the northward extension of the palazzo along Via Larga. The lobbying of Riccardi, helped obtain in 1670 the appointment of Baldi in 1670 to chief architect to the court of Grand Duke Cosimo III. In 1673 Baldi designed the Fountain in Piazza Santa Croce.