Simonetti was born in Rome, Papal States, the son of Luigi Simonetti, a prominent neoclassical sculptor in Rome.
[1] Simonetti died after a two-week illness on 23 March 1900 at his residence and studio in Balmain, Sydney, New South Wales.
[2] He was buried in the Roman Catholic section of Rookwood Cemetery.
[1][3] At the time of his death, he was designing on a statue of the late Queensland Premier Thomas Joseph Byrnes.
[4] Although there was a proposal that Simonetti's former pupil James White might continue the work, the commission was given to Melbourne sculptor Bertram Mackennal who completed the status in 1902.