Hogan was born in London, England. He was raised in the Portobello Road area on the west side of London. After leaving school at the age of sixteen, he worked various odd jobs until, after receiving a scholarship, he began a five-year program at the Royal Aircraft Establishment at Farnborough covering the practical and theoretical sides of electrical, electronic, and mechanical engineering. He first married at the age of twenty. He married three more times and fathered six children.

Hogan worked as a design engineer for several companies and eventually moved into sales in the 1960s, traveling around Europe as a sales engineer for Honeywell. In the 1970s he joined the Digital Equipment Corporation's Laboratory Data Processing Group and in 1977 moved to Boston, Massachusetts to run its sales training program. He published his first novel, Inherit the Stars, in the same year to win an office bet.

He quit DEC in 1979 and began writing full time, moving to Orlando, Florida, for a year where he met his third wife Jackie. They then moved to Sonora, California.Hogan died of a heart attack at his home in Ireland on Monday, 12 July 2010, aged 69