Ernest Genner was born on 2 June 1877 in Handsworth, Birmingham, the eldest child of Job and Elizabeth Genner, née Ely. Job Genner was an office clerk who rose to become Chief Clerk at Chance Brothers of Smethwick, one of the largest glass manufacturers in the country. Ernest was educated at King Edward's School, Birmingham, where he was a Foundation Scholar, and Captain of the School in 1893 and 1894. At the age of sixteen he won an open scholarship to read Classics at Balliol College, Oxford. His academic record at Balliol was 'one of great brilliance', according to the Oxford Magazine. He took a First in both Classical and Mathematical Mods in 1897, and a First in Greats in 1899. He won the Craven Scholarship and the Gaisford Prize for Greek Prose, and two months after graduation was elected Fellow of Magdalen College by examination. He was successively Fellow of Magdalen (1899-1903), Jesus (1903-27) and Oriel (1927-30) Colleges, making his mark as a conscientious tutor who expected high standards from his pupils. From 1909 until his death Genner represented the University on the Oxford Board of Guardians (later the Public Assistance Committee).
His Times obituary characterised him as 'a strong Nonconformist'. He joined the University's Wesley Guild in 1897, and was for many years the Guild's Senior Member, often taking the chair in the absence of the Superintendent Minister. He was a Class Leader at Wesley Memorial Church, and a Local Preacher renowned for his commitment to village Methodism. He served on the committee of the WMMS, and spent several months in 1907-08 teaching in Madras, where his Oxford contemporary F.E. Corley was on the staff of the Madras Christian College. Genner married, in September 1911, Margaret Jane Fryer, daughter of John Fryer, J.P., of Bladon, farmer and Local Preacher. Genner's dedication to public service led to his untimely death in December 1930, when he was fatally injured in a cycling accident on Christmas Eve, while travelling to a committee meeting at the London Road hospital in Headington.