Designed in 1610 by Matteo Castelli de Melide, a relative of the Borromini family. It is dedicated to Giovanni Marinoni, Paolo Burali D'Arezzo and Giuseppe Maria Tomasi, three beatified Theatines. Therefore, it is called the Blessed Souls chapel. In 1971, the body of Cardinal Giuseppe Maria Tomasi di Lampedusa was transferred here, where it can be seen beneath the altar to the right of the chapel. He was canonized on Sunday October 12, 1986 by Pope John Paul II.

The altarpiece is attributed to the Sicilian painter Francesco Manno, depicts Three Blessed Theatines: Marinoni, Burali D'Arezzo and Giuseppe Maria Tomasi.

(See better photo on the web here)