Catherine Lett was born and brought up in the Midlands. She attended the Elmfield School, Stourbridge and won a government scholarship to the Purcell School. Whilst there she took part in master classes with Emmanuel Hurwitz and the Brodsky Quartet and played in chamber music concerts at the Purcell Room and St Martin in the Fields in London. She gained her B Mus from the Guildhall School of Music and Drama where she benefited from coaching by the Takacs Quartet and master classes with Sylvia Rosenberg.

Her subsequent career has included chamber music recitals and orchestral work with such orchestras as the CBSO, English Sinfonia, the Irish Chamber Orchestra and the Belmont Ensemble of London with whom she has played Vivaldi's Four Seasons as a soloist. She teaches violin in various schools in Surrey and participates in the educational work of the City of Canterbury Symphony Orchestra's Artistic Director, Graeme Quinton-Jones, which involves helping to run workshops in schools. She was lucky to work with the CCSO when Kennedy was s soloist. On several occasions she has played with the Bernard Lanskey Trio accompanying John Suchet's Music and the Master Lecture Recital Series.