Florey continued his studies at Magdalen College, Oxford as a Rhodes Scholar under the tutelage of Sir Charles Scott Sherrington, receiving the degrees of BA in 1924 and MA in 1935. In 1925, he left Oxford to attend the University of Cambridge, during which time he won a fellowship from the Rockefeller Foundation and studied in the United States for ten months. He returned to England in 1926 and was elected to a fellowship at Gonville and Caius College, Cambridge, and a year later he received the degree of PhD.