Giovanni Bernardi (1494 – 22 May 1553), also known as Giovanni da Castel Bolognese and as Giovanni da Castelbolognese, was an Italian gem engraver and medallist who was born in Castel Bolognese, Italy. He was the son of a goldsmith and by 1530 had moved to Rome, where he had a position in the Papal mint, which also allowed him time to work for other patrons. These included Cardinal Ippolito de' Medici (1511–35), Pope Clement VII (1523–34), Cardinal Alessandro Farnese, the future Pope Paul III, as well as his grandson, also called Cardinal Alessandro Farnese. He was "a skillful composer of elegant nudes in elaborate scenes".