Ain Anger was born in Estonia. First he studied physics and mathematics, then in 1996 he began voice studies at the Academy of Music in Tallinn. At the same time he sang in the chorus of the city's opera house. He took part in several master-classes and was a prize-winner at the Tiit Kunsik Competition and the International Mirjam Helin Singing Competition. His regular tutor is Matti Pelo.
After gaining first stage experience at the Estonian National Opera in Tallinn as well as in Tartu and Riga, he moved to Germany in 2001 where he became a member of the ensemble at Leipzig Opera until 2004. While there he attracted attention for what a critic described as his "sonorous and full-bodied bass", displayed in a number of roles, some of which he was singing for the first time. In 2002 he made his debut in the USA where he was highly acclaimed in the title role of Rodion Shchedrin's The Enchanted Wanderer with the New York Philharmonic Orchestra; in addition he sang for the first time at the Deutsche Oper in Berlin as well as under the baton of Marc Minkowski in Montpellier and Perpignan. It was also under Minkowski that he made his debut at the Opera Bastille in Paris in the role of Sarastro in 2005. Since the 2004/2005 season he has been a member of the ensemble at the Vienna State Opera, where recently he was acclaimed as a "splendid Fafner" ("Salzburger Nachrichten"). He can also be heard there as Hunding (Die Walküre), King Henry (Lohengrin) and Gremin (Eugene Onegin).
He has made many successful guest appearances, for example at the Helsinki Festival, the Savonlinna Opera Festival, the festivals at Bergen and Lucerne, in Tokyo and also at the Bavarian State Opera in Munich. He has given concerts with highly regarded symphony orchestras like those of Cleveland, St Louis and Stockholm. He has performed under a great number of significant conductors, e.g. Lorin Maazel, Seiji Ozawa, Zubin Mehta, Ricardo Muti, Esa-Pekka Salonen and Franz Welser-Möst.
In October 2008, under the musical direction of Christian Thielemann, he sang the role of Hunding in a concert of the Orchestra of the Bayreuth Festival at the Abu Dhabi Classics, his performance praised as superb by the newspaper "Frankfurter Rundschau".