Irene Dalis (born Yvonne Patricia Dalis; October 8, 1925 – December 14, 2014) was an American mezzo-soprano singer, who had a long international career at the highest levels of world opera. In 1946, she received her bachelor's degree from San Jose State College (now San José State University), where she regarded herself not as a singer, but as a pianist.

Of Greek and Italian descent, Dalis grew up in San Jose, California. Dalis received her bachelor's degree from San Jose State College (now San José State University) and master's degree in music education from Teachers College of Columbia University, and she received honorary doctorates from Santa Clara University and San Jose State University.

Dalis was awarded a Fulbright scholarship and went to Europe to begin her singing career. She studied in Milan and gave her first performance of any kind at the Oldenburgisches Stadttheater in Germany. This was so successful that she was offered a contract in Oldenburg and remained there for two years between 1953 and 1955, making her professional debut there in 1953 as Princess Eboli in Verdi's Don Carlo. She then moved to the Berlin's Städtische Oper where her performance in Janáček's Jenufa led to an offer from The Metropolitan Opera, where she debuted in 1957, again as Eboli, to great applause.

One New York City reviewer, Raymond Erickson, wrote:

Her expert vocalism and musicianship were immediately apparent in the "Veil Song", which Dalis sang better than I have ever heard it sung. In the tricky ensemble with Carlo and Rodrigo in the Queen's gardens, she was just as impressive, and her sweeping, almost torrential handling of O don fatale won her a genuine ovation from the capacity audience. Everywhere, Dalis' acting went hand-in-glove with her singing. Erickson concluded that Dalis's debut was "one of the most exciting in recent seasons"

That was the first of 274 performances with the Met, over 20 seasons. She was particularly noted as Amneris in Verdi's Aïda, a part she sang 69 times at the Metropolitan. She was Brangäne when Birgit Nilsson sang first at the Met in Wagner's Tristan und Isolde in 1959, Amneris when Leontyne Price debuted in Aïda at the house in 1961 and Princess di Bouillon for Plácido Domingo's Met debut in Adriana Lecouvreur. She also performed with soprano Leonie Rysanek frequently, most notably 17 performances of Die Frau ohne Schatten by Richard Strauss, as well as in Salome and Aida.^{[citation needed]}

In 1961, Dalis appeared as the first American to sing the major role of Kundry in Wagner's Parsifal at the Bayreuth Festival. Her portrayal of this role was recorded in 1962 with Jess Thomas as Parsifal, Hans Hotter as Gurnemanz, and Hans Knappertsbusch conducting. This recording won the Grand Prix du Disc in 1964. In San Francisco, she sang the Nurse in Die Frau ohne Schatten. and Ortrud in Lohengrin, among other roles. She performed in the gala to mark the conclusion of the career of Sir Rudolf Bing

One reviewer said of her portrayal of Kundry: