Aga Mikołaj was born in the Polish town of Kutno and studied in Poznan and at the Vienna Hochschule für Musik und Darstellende Kunst, participating in masterclasses with Elisabeth Schwarzkopf and Renata Scotto. She won a special award at the Ada Sari Competition in Nowy Sacz in 1995, the Audience Prize and Handel Award at the 41st International Competition at s’Hertogenbosch, the Polish media prize for young artists in 1998 and second prize and Verdi Award at the 1999 Alfredo Kraus Competition in Las Palmas. Guest engagements have taken her to major opera houses throughout Europe, with recitals and concerts also in America. Since 2002 she has been a member of the Bavarian State Opera in Munich.