Pietro Marchelli (9 March 1806 - 29 October 1874) was an Italian architect active mainly around Reggio-Emilia.
[1] He initially studied mathematics at the University of Modena, graduating in 1830.
Among his major works are the refurbishment of the Palazzo Ducale, The design of the Foro Boario, and the design of the Synagogue of Reggio Emilia.
He became a professor of architecture at the School of Fine Arts of Reggio.
He was made Cavaliere dell'Ordine del Cristo from Portugal.