His brother Gianfrancesco Guidi di Bagno and his uncle Girolamo Colonna were also cardinals.

He was the son of Fabrizio Guidi di Bagno, Marquess of Montebello, Province of Rimini, and Laura Colonna from the Duchy of Zagarolo.

After his wife died, he left the military life to enter the ecclesiastical state.

He was consecrated a bishop in Rome on 29 March 1644 by Cardinal Antonio Barberini.

[2] Nicola Guidi di Bagno was created cardinal priest in the consistory of 9 April 1657 by Pope Alexander VII and was assigned the title of Sant'Eusebio.