The Oratorio del Santissimo Crocifisso or the Oratory of the Most Holy Crucifix is a building in central Rome, Italy. Located next to the church of San Marcello al Corso, it served as a prayer hall and meeting house for the Confraternita del SS. Crocifisso. It is best known, like the Oratorio del Gonfalone, which shares the same artists, for its Mannerist decorations.
The structure was built by Giacomo Della Porta in 1568, near the church of San Marcello, for the Confraternity of Crucifix, founded to venerate the Crucifix (crocefisso) from the nearby church. The confraternity was composed of some of the richest men in Rome, including the cardinals Ranuccio and Alessandro Farnese, nephews of the Pope. The theme of the interior decoration is the Triumph of the Cross. It employed Giovanni de' Vecchi, Cesare Nebbia, Niccolò Circignani, and Cristoforo Roncalli.