Viorica Ursuleac (26 March 1894 – 22 October 1985) was a Romanian operatic soprano. Viorica Ursuleac was born the daughter of a Greek Orthodox archdeacon, in Chernivtsi, which is now in Ukraine. Following training in Vienna, she made her operatic debut in Zagreb (Agram), as Charlotte in Massenet's Werther, in 1922. The soprano then appeared at the Vienna Volksoper (1924–26), Frankfurt Opera (1926–30), Vienna State Opera (1930–35), Berlin State Opera (1935–37), and Bavarian State Opera (1937–44). She married the Austrian conductor Clemens Krauss in Frankfurt during her time there. She was Richard Strauss's favorite soprano, and he called her "die treueste aller Treuen" ("the most faithful of all the faithful"). She sang in the world premieres of four of his operas: Arabella (1933), Friedenstag (which was dedicated to Ursuleac and Krauss, 1938), Capriccio (1942), and the public dress-rehearsal of Die Liebe der Danae (1944). Ursuleac's voice was not of great beauty, at least as recorded, but she was reckoned a great musician and actress. In the words of one colleague, the soprano Hildegard Ranczak, "Although she had a lovely, facile top, I was constantly amazed at the two hours' vocalizing she went through before each performance. Hers was, in my opinion, a marvelously constructed, not really natural voice which she used with uncanny intelligence".[this quote needs a citation] Ursuleac died at the age of ninety-one in the village of Ehrwald in Tyrol where she had resided since before the death in 1954 of her husband, Clemens Krauss.