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 at his home in Ireland on Monday, 12 July 2010, aged 69.

Hogan's style of science fiction was usually hard science fiction. In his earlier works he conveyed a sense of what science and scientists were about. His philosophical view on how science should be done comes through in many of his novels; theories should be formulated based on empirical research, not the other way around. If a theory does not match the facts, it is the theory that should be discarded, not the facts. This is very evident in the Giants series, which begins with the discovery of a 50,000 year-old human body on the Moon. This discovery leads to a series of investigations, and as facts are discovered, theories on how the astronaut's body arrived on the Moon 50,000 years ago are elaborated, discarded, and replaced.

Hogan's fiction also reflects anti-authoritarian social views. Many of his novels have strong anarchist or libertarian themes, often promoting the idea that new technological advances render certain social conventions obsolete. For example, the effectively limitless availability of energy that would result from the development of controlled nuclear fusion would make it unnecessary to limit access to energy resources. In essence, energy would become free. This melding of scientific and social speculation is clearly present in the novel Voyage from Yesteryear (strongly influenced by Eric Frank Russell's famous story "And Then There Were None"), a high-tech anarchist society in the Alpha Centauri system, a starship sent from Earth by a dictatorial government, and the events following their first contact. The story features concepts of civil disobedience, post scarcity and gift economy.

In his later years, Hogan's views tended towards those widely considered "fringe" or pseudoscientific. He was a proponent of Immanuel Velikovsky's version of catastrophism, and of the theory that AIDS is caused by pharmaceutical use rather than HIV (see AIDS denialism). He stated that he found basic evidence of evolution's being random to be lacking ... or to disprove the theory outright, though he didn't propose theistic creationism as an alternative. Hogan was skeptical of the theories on climate change and ozone depletion.

Hogan also espoused the idea that the Holocaust didn't happen in the manner described by mainstream historians, writing that he found the work of Arthur Butz and Mark Weber to be "more scholarly, scientific, and convincing than what the history written by the victors says." While such theories were seen by many to contradict his views on scientific rationality, he repeatedly stated that these theories held his attention due to the high quality of their presentation ... a quality he believed established sources should attempt to emulate, rather than resorting to attacking their originators. As such, they are consistent with the view that scientific theories should not be accepted simply because they are widely held (see, for instance, argument from authority).

In March 2010, in an essay defending Holocaust denier Ernst Zündel, Hogan stated that the mainstream history of the Holocaust includes "claims that are wildly fantastic, mutually contradictory, and defy common sense and often physical possibility."

Novels

• Inherit the Stars ISBN 978-0345289070 - May 1977 (1st book in Giants series)
• The Genesis Machine ISBN 978-0743435970 - April 1978 (republished by Baen, March 2003)
• The Gentle Giants of Ganymede ISBN 978-0345019332 - May 1978 (2nd book in Giants series)
• The Two Faces of Tomorrow ISBN 978-1593075637 - June 1979
• Thrice Upon a Time ISBN 978-0345323866 - March 1980
• Giants' Star ISBN 978-0345327208 - July 1981 (3rd book in Giants series)
• Voyage from Yesteryear ISBN 978-0671577988 - July 1982
• The Minervan Experiment ISBN 978-1125448922 - November 1982 (an omnibus edition of the first three books of the Giants series)
• Code of the Lifemaker ISBN 978-0345309259 - June 1983 (exploring ideas of a Clanking replicator robotic system)
• The Proteus Operation ISBN 978-0553050950 - October 1985
• Endgame Enigma ISBN 978-0671877965 - August 1987
• The Mirror Maze ISBN 978-0553277623 - March 1989
• The Infinity Gambit ISBN 978-0553289183 - March 1991
• Entoverse ISBN 978-0517097786 - October 1991 (4th book in Giants series)
• Multiplex Man ISBN 978-0553563634 - December 1992
• Out of Time ISBN 978-0553299717 - November 1993 (novella)
• The Giants Novels: Inherit the Stars, The Gentle Giants of Ganymede, and Giants' Star ISBN 978-0345388858 - March 1994 (republication of The Minervan Experiment)
• The Immortality Option ISBN 978-0345379153 - February 1995 (sequel to Code of the Lifemaker)
• Realtime Interrupt ISBN 978-0671578848 - March 1995
• Paths to Otherwhere ISBN 978-0671877101 - February 1996
• Bug Park ISBN 978-0671877736 - April 1997
• Star Child ISBN 978-0671878788 - June 1998
• Outward Bound ISBN 978-0812571912 - March 1999 (A Jupiter Novel)
• Cradle of Saturn ISBN 978-0671578664 - June 1999
• The Legend that was Earth ISBN 978-0671318406 - October 2000
• Martian Knightlife ISBN 978-0743435918 - October 2001
• The Anguished Dawn ISBN 978-0743498760 - June 2003 (sequel to "Cradle of Saturn")
• Mission to Minerva ISBN 978-1416520900 - May 2005 (5th Book in the Giants series)
• Echoes of an Alien Sky ISBN 978-1416521082 - February 2007
• Moon Flower ISBN 978-1416555346 - April 2008
• Migration ISBN 978-1439133521 - May 18, 2010

Short story collections

• Minds, Machines & Evolution ISBN 978-0553272888 - 1988 (republished by Baen, December 1999)
• Rockets, Redheads & Revolution ISBN 0671578073 - April 1999 (short stories and essays)
• Catastrophes, Chaos & Convolutions (title as published; was to be Catastrophes, Creation & Convolutions) ISBN 978-1416509219 - December 2005 (short stories and essays)

Non-fiction

• Mind Matters - Exploring the World of Artificial Intelligence ISBN 978-0614282023 - March 1997
• Kicking the Sacred Cow: Heresy and Impermissible Thoughts in Science ISBN 978-1416520733 - July 2004