British biochemist who, with Gerald M. Edelman (Edelman, Gerald Maurice), received the 1972 Nobel Prize for Physiology or Medicine for his contribution to the determination of the chemical structure of an antibody.

Porter was educated at the University of Liverpool (B.S., 1939) and the University of Cambridge (Ph.D., 1948) and worked at the National Institute for Medical Research at Mill Hill from 1949 to 1960. He served as professor of immunology at St. Mary's Hospital Medical School, London, until 1967, when he joined the faculty at the University of Oxford.

Porter approached the problem of antibody structure by using an enzyme, papain, to cleave the blood's immunoglobulin molecule into functionally different fragments, which were then amenable to structural analysis. Edelman (Edelman, Gerald Maurice), working independently, used different methods to break up the molecule, and he concluded that it was a multichain entity rather than a single chain of amino acids. Porter and his research team were then able to determine the now universally accepted four-chain model of the antibody. Using his fragmentation technique, Porter studied the chains of the molecule separately, while Edelman worked on the whole molecule. By 1969 a complete model of the molecule, comprising more than 1,300 amino acids, had been achieved.