The Endellion String Quartet is a British string quartet named after St Endellion in Cornwall.

The quartet was formed in 1979 and has been 'Quartet in Residence' at Cambridge University since 1992. It has an extensive discography and appears in concert halls around the world. The quartet received the 1996 award for 'Best Chamber Ensemble' from the Royal Philharmonic Society. They have released their recording of the cycle of Beethoven's quartets, string quintets and quartet fragments for Warner Classics and Jazz.