Born in Australia on 8 August 1860, the eldest child of George Brice Pennell, civil engineer, and his wife, *née* Mist. He was educated at Lancing College and at Lincoln College, Oxford, where he was a scholar and took third-class honours in Classical Moderations in 1881. He entered Guy's Hospital Medical School as a scholar in 1883, and won the Gurney Hoare prize. He served as assistant demonstrator of anatomy, and as house surgeon, clinical assistant in the ophthalmic department, and resident obstetrician at Guy's, and contributed papers to the *Guy's Hospital Reports* and other journals. After serving as clinical assistant at the Royal London Ophthalmic Hospital, Moorfields, and as resident medical officer at the Evelina Hospital for Sick Children, Pennell emigrated to the Argentine where he practised at Buenos Aires and served as surgeon to the Argentine Great Southern Railway. Pennell married: (1) in 1893 Miss Lafone, by whom he had three daughters; and (2) in 1923 A Landon, who survived him. There were no children of this second marriage. He died at Court Meadow, Moretonhampstead, Newton Abbot, Devon, where he had lived in retirement for many years, on 14 April 1944, aged 83.