Novello was born David Ivor Davies in Cardiff, Wales, to David Davies (c. 1852–1931), a rent collector for the city council, and his wife, Clara Novello Davies, an internationally known singing teacher and choral conductor. As a boy, Novello was a successful singer in the Welsh Eisteddfod. His mother set up as voice teacher in London, where he met leading performers, including members of George Edwardes's Gaiety Theatre company, classical musicians such as Landon Ronald, and singers such as Adelina Patti. Another of his mother's associates was Clara Butt, who taught him to sing "Abide with Me" when he was a boy of six.