(b. ca. 1565, Vicenza, d. 1611, Roma)
Italian sculptor, born in Vicenza. He trained in the school of Alessandro Vittoria in Venice. He made his debut in Rome in 1597 with work on the chapel of the Angeli in the church of the Gesů, he made a few little stucco putti.
The work which assured Mariani's success in 1600 was a series of eight statues of saints in niches in the church of San Bernardo alle Terme, a church built in one of the four corner rotundas of the Bath of Diocletian. The church had been refurbished at the end of the sixteenth century, thanks to the generosity of Caterina Sforza, countess of Santafiora. At San Bernardo alle Terme he collaborated with the Tuscan sculptor Francesco Mochi.
Mariani was also given commissions for the Aldobrandini Chapel in Santa Maria sopra Minerva. Working alongside him there was Nicolas Cordier, a sculptor from Lorraine. The two sculptors had met when they, and other late Mannerist sculptors, were working in the Borghese Chapel (Cappella Paolina) in Santa Maria Maggiore. Here he produced a somewhat affected work, the Religion, commissioned for one of the tombs in the chapel.
After his death in 1611 Francesco Mochi took over the workshop and completed an unfinished statue of St John the Evangelist for the Borghese Chapel in Santa Maria Maggiore. Had Mariani lived longer, he might have established himself as the major presence in Roman sculpture; his influence did, however, linger in the works of Francesco Mochi.