Rinaldo degli Albizzi (1370–1442) was an Italian nobleman, a member of the Florentine family of the Albizzi. Together with Palla Strozzi, he was the main opponent of Cosimo de' Medici's rise in Florence.
After the Volterran revolt against Florence in 1428, Rinaldo degli Albizzi was sent to 'reacquire' Volterra from rebels led by priors and Giovanni di Contugi. Afterwards, Rinaldo incited Niccolò Fortebraccio to "attack the Lucchese under cover of some fictitious quarrel", an action that led Florence to the conquest of Lucca. During this campaign, Rinaldo degli Albizzi was accused of attempting to increase his own wealth through sacking. He was eventually removed from his position and recalled to Florence.
Later, in the 1430s, Rinaldo convinced several prominent nobles to strike out against Cosimo de' Medici, whom he feared was getting too powerful. Eventually, Rinaldo helped Bernardo Guadagni, a candidate for a position among the Signori, pay off his debts, which had been disqualifying him from running for office. Guadagni won the position of Gonfaloniere of Justice. Through Guadagni, Rinaldo summoned Cosimo to the palace, where he was captured. After a short trial, Cosimo was sentenced to 20 years' exile from Florence.
However, with the downturn of Florentine fortunes in the war with Milan, Cosimo returned with popular acclamation barely a year later, and Rinaldo was in his turn exiled. He died at Ancona.
Rinaldo is portrayed by Lex Shrapnel in the 2016 television series Medici: Masters of Florence.