The Zoellner Quartet was a string quartet active during the first quarter of the 20th century. It was once described as "the most celebrated musical organization in the West which devotes its energies exclusively to the highest class of chamber music." After training in Europe, the group in its prime years toured widely throughout the United States. Although all members were natives of Brooklyn, New York, the ensemble formed a strong early association with Belgium and in publicity often billed itself as "The Zoellner Quartet of Brussels"; its ultimate base of operations was in California. With one brief interruption at the end of World War I, the membership remained constant throughout the quartet's existence: Joseph Zoellner and his children Antoinette; Amandus; and Joseph, Jr. A second "Zoellner Quartet" was later formed by Joseph, Jr. and three unrelated musicians.

The Flonzaley Quartet was a string quartet organized in Manhattan, New York City, in 1902. The group disbanded in 1929.