Albert of Brandenburg (28 June 1490 - 24 September 1545) was the Archbishop of Mainz from 1514 until 1545, the Margrave of Brandenburg from 1499 until 1513, the Archbishop of Magdeburg from 1513 until 1545, and the Bishop of Halberstadt from 1513 until 1545.

Albert was the second son of the Elector Margrave John Cicero of Brandenburg. In 1499 after John's death, Albert and his elder brother Joachim I Nestor were made the Margraves of Brandenburg, but only Joachim held the electorate. In 1506 Albert went to the university in Frankfurt. In 1513 Albert resigned his margravial title to become the Archbishop of Magdeburg and the Bishop of Halberstadt. The following year Albert was also elected the Archbishop of Mainz, who chose him oout of defiance of the Dukes of Saxony who seemed certain to annex Erfurt.

In order to pay for the pallium of Mainz and to pay the expenses of his simony, Albert borrowed 21,000 dorats from Jacob Fugger. In order to pay that loan he invited Johann Tetzel to sell indulgences, which is considered by many to be the cause of Martin Luther's 95 Theses. In 1515 he hired Ulrich of Hutten and attempted to reform the archbishopric of Mainz from within. In 1517 Martin Luther nailed his theses to the cathedral door in Wittenberg and sent a copy to Albert, and he sent a copy to Rome suspecting them of heresy. He held a synod to try and mediate and reform the Roman Catholic church which failed, and contrasted him from other figures during the initial stages of the Reformation.

In the Imperial election of 1519 Albert's vote was much sought after by the partisans of Archduke Charles I of Austria and King Francis I of France. Albert appears to have received a large sum of money from both sides, and he eventually voted for Charles who was hence elected. Albert's friendship with Ulrich of Hutten and his liberalism raised hopes among Lutherans of his conversion, but after the Peasant's War in 1525 he distancd himself from the Protestants. In 1530 at Augsburg he called for peace and a united stand against the Turks. In 1534 he established peace between the Emperor and the Protestant Duke George of Saxe-Meissen. In 1538 however he joined the Catholic League and his illegal execution of Hans von Schönitz led Martin Luther to publish a violent and libellious pamphlet against him.

In order to raise funds, he sold religious libery to the citizens of Magdeburg for 500,000 florins. By 1540 he had become more intolerant towards Protestants and he invited the Jesuits to Mainz, the first catholic prince to do so. Albert died in Aschaffenburg in 1545. During his life he had promoted the arts and sciences, built a university in Frankfurt and commissioned Matthias Grünewald to adorn his residence at Moritzburg.

Preceded by:

Albert III of Brandenburg

Succeeded by:

John Cicero Margrave of Brandenburg
1499 - 1513
with... Joachim I Nestor
1499 - 1513
Joachim I Nestor
Uriel of Gemmingen Archbishop of Mainz
1514 - 1545
Sebastian of Heusenstamm
Ernest of Saxony Archbishop of Magdeburg
1513 - 1545
John Albert of Brandenburg
Ernest II of Saxony Archbishop of Halberstadt
1513 - 1545
John Albert of Brandenburg