Robert Silverberg was born in New York City on 15 January 1935 to Michael and Helen Silverberg, an only child. He tends to keep his personal life to himself, but he has made allusions to being a lonely and bitter child who found a sort of release in science fiction and fantasy.

In 1949 he started a science fiction fanzine called Spaceship and made his first professional sale to Science Fiction Adventures, a non-fiction piece called Fanmag, in the December 1953 issue. His first professional fiction publication was Gorgon Planet in the February 1954 issue of the British magazine Nebula Science Fiction. His first novel, Revolt on Alpha C, was published in 1955.

In 1956 he graduated from Columbia University, having majored in Comparative Literature, and married Barbara Brown, an electronics engineer specializing in radar and optics (according to a dust-jacket bio). His literary background would surface eventually in his writing, but for a time, he seems to have kept the straight separate from the science fiction he wrote, as it was pure adventure stuff with little that would indicate interests beyond the typical science fiction of the day.