He wrote several books for the Target novelisations, including two published posthumously.
He sometimes wrote under the pen name Ian Don.
After graduating from Oxford University in 1969, Marter worked at the Bristol Old Vic theatre, where he was a stage manager and acted in various minor roles. To supplement his low actor's wages, he worked for a time as a milkman and a schoolteacher.
In 1970 he auditioned for the regular role of Captain Mike Yates in the eighth season of Doctor Who. Although he was offered the part, he was unable to accept due to other commitments. He sufficiently impressed the production team to be kept in mind however, and was cast in a supporting role in the 1973 story Carnival of Monsters, broadcast as part of the tenth season of the programme.
In 1974, he was cast as companion Harry Sullivan, a character developed by the production team when they thought the Fourth Doctor might be portrayed by an older actor who would be unable to handle the more physical action scenes. However, after Tom Baker, who was forty, was cast, this was no longer an issue. Harry was written out after just one season, despite being a popular character and gelling with Baker and other lead Elisabeth Sladen. Marter was the third Doctor Who regular to be cast following a guest appearance; the first two were Peter Purves and Nicholas Courtney.
Marter remained involved with Doctor Who after his departure from the cast. He co-wrote the script for a potential feature film version, provisionally titled Doctor Who Meets Scratchman in collaboration with Baker and film director James Hill, although this never came to pass. The intention was to have Baker's Doctor come face to face with Scratchman, an ancient British word for the devil. The finale of the film would have taken place on a giant pinball table, the holes in the table portals to other dimensions. The project fizzled out due to lack of funding and the dire state of the British film industry. However, much of the material written by Marter and Baker for that project would be adapted, by Baker himself with James Goss, for the 2019 novel Scratchman.
He also became involved with the writing of novelisations of Doctor Who stories for Target Books, penning nine adaptations in the late 1970s and early 1980s. Marter's novelisations were controversial, most notably for his use of the word 'bastard' in his novelisation of The Enemy of the World.
The last of Marter's Doctor Who novelisations was The Rescue, which was completed by range editor Nigel Robinson after Marter's unexpected death. Marter is, to date, one of only six Doctor Who actors (the others being Colin Baker, David Banks, Glyn Jones, Mark Gatiss and Tom Baker; original series writer Victor Pemberton also appeared as an actor) to write licensed fiction based upon the series.
Marter also wrote an original spin-off novel for Target, Harry Sullivan's War, starring the character he had played on screen, published in 1986, only weeks before his death; this was the second original Doctor Who-related novel ever published, after Turlough and the Earthlink Dilemma. Marter planned a sequel and an adaptation of the unused Doctor Who Meets Scratchman script at the time of his death.
In addition to his Doctor Who novelisations, he adapted several 1980s American films, such as Splash (1984) and Down and Out in Beverly Hills (1986) for Target and their Star Books imprint. Some of these books were published under the pen name Ian Don.
Marter's acting career outside of Doctor Who consisted mainly of guest roles in series such as the BBC's Bergerac (in 1985) and Granada Television's The Return of Sherlock Holmes (in 1986). He also had minor roles in films, such as The Abominable Dr. Phibes (1971) and The Medusa Touch (1978).
Marter married Rosemary Heyland in 1968 and had two sons, Rupert and Toby. He died suddenly at his home in London on his forty-second birthday in 1986 (some sources erroneously give his date of death as being two days later, 30 October) after suffering a heart attack brought on by complications of type 1 diabetes. He has the sad distinction of being the first companion actor to pass away, and only the third major Doctor Who actor to die (the first was Roger Delgado in 1973, follwed by William Hartnell two years later).
- The Ark in Space
- The Sontaran Experiment
- Genesis of the Daleks
- Revenge of the Cybermen
- Terror of the Zygons
- The Android Invasion
- Doctor Who and the Ark in Space
- Doctor Who and the Sontaran Experiment
- Doctor Who and the Ribos Operation
- Doctor Who and the Enemy of the World
- The Dominators
- The Invasion
- The Reign of Terror
- The Rescue
The Companions of Doctor Who
- REF: Who-ology: The Official Miscellany
- Doctor Who Official (28 October 2012). Ian Marter (1944 –1986) was born on this day… We remember him fondly as Harry Sullivan.. Twitter. Retrieved on 13 December 2016.
- Whyte, Nicholas (19 March 2007). The Doctor Who novels of Ian Marter. Strange Horizons. Retrieved on 13 December 2016.
- Find a Grave
- Courtney, Nicholas; McManus, Michael (2005) Still Getting Away With It: The Life and Times of Nicholas Courtney, ISBN: 1871330734
- DWM 501