Turtledove was born in Los Angeles, California on June 14, 1949, and grew up in Gardena, California. His paternal grandparents, who were Romanian Jews, had first emigrated to Winnipeg, Manitoba, before moving to the U.S. and California. He was educated in local public schools in early life.
After dropping out during his freshman year at Caltech, Turtledove attended UCLA, completing his undergraduate degree and receiving a Ph.D. in Byzantine history in 1977. His dissertation was titled The Immediate Successors of Justinian: A Study of the Persian Problem and of Continuity and Change in Internal Secular Affairs in the Later Roman Empire During the Reigns of Justin II and Tiberius II Constantine (AD 565–582).
In 1979, Turtledove published his first two novels, Wereblood and Werenight, under the pseudonym "Eric G. Iverson." Turtledove later explained that his editor at Belmont Tower did not think people would believe the author's real name was "Turtledove" and came up with something more Nordic. He continued to use the "Iverson" name until 1985. Another early pseudonym was "Mark Gordian."
That year he published Herbig-Haro and And So to Bed under his real name. Turtledove has recently begun publishing historical novels under the pseudonym "H.N. Turteltaub" (Turteltaube means turtle dove in German). He published three books as Dan Chernenko (the Scepter of Mercy series).
He has written several works in collaboration, including The Two Georges with Richard Dreyfuss, "Death in Vesunna" with his first wife, Betty Turtledove (pen-name, Elaine O'Byrne); Household Gods with Judith Tarr; and others with Susan Shwartz, S.M. Stirling, and Kevin R. Sandes.