Santo Spirito in Sassia is a 16th century titular and former hospital church. Work began under Baldassare Peruzzi (1481-1536) and continued under Antonio da Sangallo the Younger (1484-1546). The façade was added under Pope Sixtus V (r. 1585-1590), perhaps to a design by Ottaviano Nonni (1536-1606), better known as il Mascherino.
Nave
The church has a single nave with five chapels to the left and four to the right.
The beautiful wooden ceiling was installed during the reign of Pope Paul III (r. 1534-49).
Apse
The apse has a fresco cycle which has been ascribed to the Florentine painter Jacopo Zucchi (c. 1541- c. 1592). The theme is the Descent of the Holy Spirit at Pentecost.