Ernst Wallfisch (27 May 1920 in Frankfurt am Main – 8 May 1979 in Northampton, Massachusetts) was a prominent viola soloist, recording artist and pedagogue, primarily remembered along with his wife, pianist Lory Wallfisch, as partners of the Wallfisch Duo.

Born into a musical family, Ernst Wallfisch immigrated to Bucharest, Romania in 1926. He studied violin with Cecilia Nitzulescu-Lupu at the Bucharest Conservatory. Having a strong attraction to the sound of the viola, he turned his attentions to the instrument at the age of 14 and made his highly praised début on viola at 18. At the Conservatory, he met violinist-composer George Enescu, who was one of his greatest sources of inspiration, and his wife Lory, a pianist with whom he started to perform during the War. They married in November 1944. Yehudi Menuhin heard the duo perform in Bucharest in May 1946 on the occasion of his first trip to Romania. Menuhin was deeply moved by their playing and helped the couple immigrate to the United States. They became American citizens in 1953, and had their only child, musician Paul Wallfisch in 1962.

Ernst Wallfisch was a member of the Pro Musica Quartet and the Bucharest Philharmonic Orchestra prior to his immigration, later a member of the Dallas Symphony Orchestra, Cleveland Orchestra, and principal violist with the Detroit Symphony Orchestra from 1953 to 1955. As the Wallfisch Duo, he performed throughout the United States, Canada, South America, Europe, North Africa and Israel. Pablo Casals provided another influence and long-lasting inspiration, which culminated in chamber music collaborations at several Pablo Casals Festivals in Prades between 1955 and 1961. As viola pedagogue, he taught at the Mozarteum University of Salzburg and at the Lucerne Conservatory. Both Ernst and Lory Wallfisch joined the music faculty of Smith College at Northampton, Massachusetts in 1964. Ernst Wallfisch died suddenly of a heart attack in 1979.

Wallfisch was also a master viola da gamba player, even making recordings.

Lory Wallfisch donated her husband's collection of viola music, approximately 300 items, to the Primrose International Viola Archive at Brigham Young University.