The Juilliard String Quartet is a classical music string quartet founded in 1946 at the Juilliard School in New York. The original members were Robert Mann and Robert Koff on violin, Raphael Hillyer on viola, and Arthur Winograd on cello; Current members (as of 1997) are Joel Smirnoff and Ronald Copes on violin, Samuel Rhodes on viola, and Joel Krosnick on cello.

The quartet is currently quartet-in-residence both at the Juilliard School and the Library of Congress. It has also received numerous awards including four Grammys and membership in the National Academy Recording Arts and Sciences’ Hall of Fame.

The quartet plays a wide range of classical music, having recorded works by composers such as Beethoven, Mendelssohn, Bartók, Debussy, and Shostakovich, while also promoting more contemporary composers such as Elliott Carter and Milton Babbitt.

It has also performed with other noted musicians such as Aaron Copland, Yo-Yo Ma, and Maurizio Pollini.The quartet began recording with Sony Classical (formerly Columbia Records and CBS Masterworks) in 1949, and the group's discography currently numbers over 100 items, including repertoire well-travelled and unfamiliar.

Their early 1950s recordings of the six Bartok string quartets on the Columbia Records label and various works recorded for the RCA Living Stereo label (c. 1958-1962) are particularly acclaimed.