Maria Eleonora of Brandenburg was a German princess and Queen of Sweden as the consort of King Gustav II Adolph.
She was a daughter of John Sigismund, Elector of Brandenburg, and Anna, Duchess of Prussia, daughter of Albert Frederick, Duke of Prussia.
In 1620, Maria Eleonora married Gustavus Adolphus with her mother's consent, but against the will of her brother George William, Elector of Brandenburg, who had just succeeded her father. She bore her husband a daughter, Christina in 1626.