George Wald was born in New York City, the son of Ernestine (Rosenmann) and Isaac Wald, Jewish immigrant parents. He was a member of the first graduating class of the Brooklyn Technical High School in New York in 1922. He received his Bachelor of Science degree from New York University in 1927 and his PhD in zoology from Columbia University in 1932. After graduating, he received a travel grant from the US National Research Council. Wald used this grant to work in Germany with Otto Heinrich Warburg where he identified vitamin A in the retina. Wald then went on to work in Zurich, Switzerland with the discoverer of vitamin A, Paul Karrer. Wald then worked briefly with Otto Fritz Meyerhof in Heidelberg, Germany, but left Europe for the University of Chicago in 1933 when Adolf Hitler came to power and life in Europe became more dangerous for Jews. In 1934, Wald went to Harvard University where he became an instructor, then a professor.

Wald died in Cambridge, Massachusetts. He was married twice: in 1931 to Frances Kingsley and in 1958 to the biochemist Ruth Hubbard. He had two sons with Kingsley—Michael and David; he and Hubbard had a son—the award-winning musicologist and musician Elijah Wald—and a daughter, Deborah, a prominent family law attorney. He was an atheist.

He was elected to the National Academy of Sciences in 1950 and in 1967 was awarded the Nobel Prize for Physiology or Medicine for his discoveries in vision. In 1966 he was awarded the Frederic Ives Medal by the OSA and in 1967 the Paul Karrer Gold Medal of the University of Zurich.

Wald spoke out on many political and social issues and his fame as a Nobel laureate brought national and international attention to his views. He was a vocal opponent of the Vietnam War and the nuclear arms race. Speaking at MIT in 1969 Wald bemoaned that "Our government has become preoccupied with death, with the Business of killing and being killed." In 1970, Wald predicted that “civilization will end within 15 or 30 years unless immediate action is taken against problems facing mankind.” In 1980, Wald served as part of Ramsey Clark's delegation to Iran during the Iran hostage crisis.

With a small number of other Nobel laureates, he was invited in 1986 to fly to Moscow to advise Mikhail Gorbachev on a number of environmental questions. While there, he questioned Gorbachev about the arrest, detention and exile to Gorki of Yelena Bonner and her husband, fellow Nobel laureate Andrei Sakharov (Peace, 1975). Wald reported that Gorbachev said he knew nothing about it. Bonner and Sakharov were released shortly thereafter, in December 1986.