Of Swedish ancestry, Seaborg was born at Ishpeming, Michigan, grew up in South Gate, a suburb next to Watts in Los Angeles, took his A. B. degree at the University of California, Los Angeles in 1934, and his doctorate at the University of California, Berkeley in 1937.
As a graduate student in the 1930s doing wet chemistry research for his advisor Gilbert Newton Lewis, Seaborg devoured the text Applied Radiochemistry by Otto Hahn, of the Kaiser Wilhelm Institute for Chemistry in Berlin. For several years, Seaborg conducted important research in artificial radioactivity using the Lawrence cyclotron at Cal Berkeley. He was excited to learn from others that nuclear fission was possible -- but also chagrined, as his own research might have led him to the same discovery.
Seaborg also became expert in dealing with the great Berkeley physicist Robert Oppenheimer. Oppenheimer was so quick and knew so much, he had a habit of answering a junior man's question before it had even been stated. Often the question answered was more profound than the one asked, but of little practical help. Seaborg learned to state his questions to Oppenheimer very quickly and succinctly, and this habit of asking succinct questions stood Seaborg in good stead all his professional life.
He created plutonium, americium, curium, berkelium, and californium at Berkeley and, with Edwin McMillan, shared the Nobel Prize in Chemistry in 1951 for the creation of the first transuranium elements.
In the same year in which he produced plutonium, 1941, he also discovered that the isotope U235 undergoes fission under appropriate conditions. He therefore was responsible for two different approaches to the development of nuclear weapons. At this time he was transferred to the Manhattan Project and was part of Enrico Fermi's team which achieved the first nuclear chain reaction in 1942.
Seaborg got married in 1942, to Helen Griggs, the secretary of Ernest Lawrence. Under wartime pressure, Seaborg and Griggs took the train from Los Angeles to Chicago, and got off in Caliente, Nevada for what they thought would be a quick wedding. But when they asked for City Hall, they found Caliente had none -- they would have to go 25 miles north to Pioche, the county seat. But how?
Happily, one of Caliente's newest deputy sheriffs turned out to be a brand new graduate of the Berkeley chemistry department, who was happy to do a favor for Glenn Seaborg. The new deputy sheriff arranged for the wedding couple to ride up and back to Pioche in a mail truck. The witnesses at their wedding were a clerk and a janitor. (Wedding said in obit to be on June 6, but inconsistent with below)
On April 19, 1942, Seaborg reached Chicago, and joined up with the chemistry group at the Metallurgical Lab at the University of Chicago, where Fermi and his group had already learned how to convert U238 to plutonium using a chain-reacting pile. Seaborg's role was to figure out how to extract the tiny bit of plutonium from the mass of uranium.
Seaborg served as chairman of the United States Atomic Energy Commission from 1961 to 1971. In 1976, when the Swedish king visited the United States, Seaborg played a major role in welcoming the king.
The element seaborgium was named for him in honor of his accomplishments. It was so named while he was still alive, which proved extremely controversial. For the remainder of his life, Seaborg was the only person in the world who could write his address in chemical elements: Seaborgium, Lawrencium, Berkelium, Californium, Americium (Glenn Seaborg, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America).
He had six children with Helen, of whom the first, Peter Glenn Seaborg, died in 1997. The others were Lynne Seaborg Cobb, David Seaborg, Steve Seaborg, and Dianne Seaborg.