Boycott was educated at Oriel College, Oxford, taking a first in physiology in 1898. In 1900 he entered St. Thomas's Hospital London, and qualified for his BM in 1902. In 1913, he was elected professor of pathology at the University of Manchester. In this post, he strongly emphasised the importance of clinical research; his own interests were in the study of nephritis, the regulation of blood volume and the composition of tissue fluids in normal and nephritic animals. He resigned the chair in 1914 to become professor of pathology at University College Hospital in London, where he remained until 1935. As a pathologist he stressed the importance of the organism's ability to repair injury. He was a Fellow of the Royal Society.