Barbara of Brandenburg (1423 – 7 November 1481) was a Marchioness consort of Mantua, married in 1433 to Ludovico II Gonzaga, Marquis of Mantua.
Barbara was the daughter of John, Margrave of Brandenburg-Kulmbach, and Barbara of Saxe-Wittenberg and a niece of Holy Roman Emperor Sigismund. Her marriage took place in 1433, when she was only ten years old, and she spent the latter part of her childhood in Mantua. She was active as the political adviser of her spouse with the responsibility of foreign diplomatic correspondence, in particular when it pertained to relations between Mantua and Germany. She is regarded as an important figure in the Italian Renaissance and was a student of Vittorino da Feltre.
Barbara is portrayed in the novel The Princess of Mantua by Marie Ferranti.