Erdmann August, Hereditary Prince of Brandenburg-Bayreuth (8 October 1615 – 6 February 1651), was a member of the House of Hohenzollern and Hereditary prince (German: Erbprinz) of Brandenburg-Bayreuth.

He was the seventh of the nine children of Christian, Margrave of Brandenburg-Bayreuth by his wife, Marie of Prussia.

In fact, he was the third-born son but the only one to survive into adulthood; his two older brothers Georg Frederick (b. and d. 1608) and Christian Ernst (b.

Erdmann August himself died four years later, aged thirty-five, in the middle of the preparations of his wedding with Sophie Agnes of Mecklenburg-Schwerin.

Because he predeceased his father, his son Christian Ernst succeeded as Margrave of Brandenburg-Bayreuth in 1655.