Walter Gilbert (born March 21, 1932) is an American physicist, biochemist, entrepreneur, and molecular biology pioneer. He was awarded the 1980 Nobel Prize in Chemistry with Paul Berg and Frederick Sanger. Gilbert and Sanger were recognized for their pioneering work in devising methods for determining the sequence of nucleotides in a nucleic acid. Walter Gilbert also first proposed the term RNA world hypothesis for the origin of life, for a concept first proposed by Carl Woese in 1967. He is a co-founder of the biotech start-up company Biogen and was the first chairman on the board of directors.
He was born in Boston, Massachusetts and educated at Harvard University and the University of Cambridge, later joining the faculty at Harvard. His approach to the first synthesis of insulin lost out to Genentech's approach which used genes built up from the nucleotides rather than from natural sources.
Walter Gilbert is currently the chairman of the Harvard Society of Fellows.