Grimaldi was an Italian painter, printmaker and architect. Little is known of his early years although he may have trained in his native Bologna, probably in the circle of the Carracci. In 1626 he moved to Rome and became associated with the group of artists working around Pietro da Cortona. Grimaldi was a member of the Academy of Saint Luke, which he entered in 1635, according to documents. Among his first known works, which are all in fresco, is the decoration of the chapel of Santa Anna in the church of Santa Maria dell’Anima, the vault of the gallery of the Palazzo Peretti-Almagia (in collaboration with Perrier and Ruggieri), and the vault of the main reception room in the Palazzo Santacroce ai Catinari. These early schemes reveal the importance that Grimaldi gave to the landscape backgrounds in his works, a genre that would later become his speciality.
Between 1647 and 1649 Grimaldi was involved in the construction of the Villa Pamphilj in Rome, working as assistant architect, garden designer and painter to Alessandro Algardi. Grimaldi also worked outside Rome and between 1649 and 1651 he is documented in Paris working on various commissions including the decoration of Cardinal Mazarin’s palace (now the Bibliothèque Nationale) in collaboration with Giovanni Francesco Romanelli, the Palais du Louvre, and the Jesuit church. On his return to Rome, Grimaldi worked under the supervision of Pietro da Cortona, executing part of the decoration of the gallery of the Quirinale palace for Popes Alessandro VII and Clement IX. For this scheme he painted scenes including Moses and the burning Bush and The Explorers of the Promised Land. Grimaldi was again absent from Rome between 1656 and 1659, when he was probably engaged on the paintings for the chapel of the Immaculate Conception in Tivoli cathedral. His last years were devoted to fresco painting particularly landscapes surrounded by decorative cartouches with foliage, painted for the leading residences in Rome, notably the Palazzo Borghese and Palazzo Muti-Papazzuri, as well as the Villa Falconieri in Frascati.