Roth was born in Dalston, London, on 5 March 1899. His parents were Etty and Joseph Roth, and Cecil was the youngest of their four sons. In childhood, Cecil received a traditional Jewish religious education, including studying Hebrew, with Jacob Mann. He went to school at City of London School. He fought in the First World War, seeing active duty in France in 1918.
On his retirement from Oxford in 1964, at the invitation of Joseph H. Lookstein, Roth became a visiting professor at Bar-Ilan University, Israel, moving to Jerusalem. However, within a month of his arrival he was attacked in a publication by Rabbi Avraham Yitzhak Bromberg for allegedly arguing that Moses never existed -- when in fact he had noted others' scepticism about Moses' existence and argued that Moses had in fact lived. The accusation prompted a scandal, and Roth suffered a heart attack in November 1964. Roth's wife Irene attributed the heart attack partly to stress of migrating, and partly to the stress of the accusations. Roth stood down from his position at the University early in 1965, citing ill health. He went on to hold a position at the City University of New York (1966-1969) while working as general editor of the Encyclopaedia Judaica, dying in post shortly after the first edition of the encyclopaedia was completed.
Roth died, aged 71, on 21 June 1970 in Jerusalem.
Back page London Jewish Guardian 28 Dec 1928, featuring a letter by Roth.