Morwenna Del Mar enjoys a busy and varied career as a soloist and chamber musician (as a member of the Del Mar Piano Trio), and is increasingly in demand as an orchestral principal player. She is the principal cello of Covent Garden Sinfonia, a member of the cello section of the BBC Symphony Orchestra, and previously held the position of Principal Cello (No.2) with the Orchestra of Opera North. In 2022 she was offered the position of Principal Cello with the Auckland Philharmonia Orchestra in New Zealand.

Morwenna has performed as guest principal with orchestras such as the London Philharmonic Orchestra (including multiple Glyndebourne seasons), BBC Symphony Orchestra, BBC Concert Orchestra, BBC Philharmonic Orchestra, Orchestra of Opera North, Orchestra of Scottish Opera, Auckland Philharmonia Orchestra, RTÉ Concert Orchestra, English Touring Opera and Rambert Dance Company. She was the continuo cellist for the Royal Opera House, Covent Garden’s 2019 production of Don Giovanni.

Alongside this, she plays regularly with the London Symphony Orchestra, and has toured extensively across Europe, the Americas, India, the Far East, and Australia. Her playing is widely recorded on film, television, and video game soundtracks, as well as on numerous classical albums, including Grazyna Bacewicz's Cello Quartet, and as a soloist with the BBC Singers.

She has given solo and chamber performances at the Purcell Room, Wigmore Hall, Leeds Town Hall, The Reid Concert Hall in Edinburgh and in King's College Chapel, Cambridge, and has appeared as soloist in concertos by Elgar, Saint-Saëns and Schumann, Tchaikovsky's Variations on a Rococo Theme, the Dvorak Rondo, the Beethoven Triple Concerto (with the Del Mar Piano Trio), and the Brahms Double Concerto (with violinist Francesca Barritt).

Morwenna read music at Cambridge University, graduating in 2005. She continued her studies as a cellist at the Royal Academy of Music (where she was awarded a postgraduate performance diploma with distinction and a DipRAM for an outstanding final recital), and for two years with Professor Steven Doane at the Eastman School of Music, New York, graduating in 2009 with a Masters in Music and an Orchestral Studies Diploma. Morwenna was principal cello of the National Youth Orchestra of Great Britain, and a member of the European Union Youth Orchestra. Other orchestral training included a Leverhulme Orchestral Fellowship at the Royal Academy of Music, an Orchestral Studies Diploma at the Eastman School of Music, and as a participant of the London Symphony Orchestra's String Experience Scheme was awarded the LSO's PROMIS award for most outstanding student.