June Ellis was born on May 10, 1930 in Wrexham, Wales, UK, daughter of Frank Ellis, an accountant. She raised in rural Denbighshire. She worked on the Chester Chronicle. In 1951, she married Ronald Knox-Mawer (1925-2009), a barrister and member of the colonial judiciary, they had a son a and a daughter. The marriage lived in Arabia and Fiji, that inspired her writing. In 1972, they returned to UK.
Published since 1961, in 1992 her novel Sandstorm won the Romantic Novel of the Year Award by the Romantic Novelists' Association.
Knox-Mawer was also a noted broadcaster which included a long time association with BBC Radio 4’s Woman’s Hour.
June died on April 19, 2006, survived by her husband and children.