Matt Helm, a fictional character created by American author Donald Hamilton, is a U.S. government counteragent—a man whose primary job is to kill or nullify enemy agents—not a spy or secret agent in the ordinary sense of the term as used in spy thrillers.
Helm appeared in 27 books over a 33-year period beginning in 1960 and quickly established himself as one of the most tough-minded, pragmatic, and competent of all fictional agents, whatever their roles. The series was also notable for its between-books continuity, which was somewhat rare for the genre. In the latter books, however, Helm's origins as a youthful man of action in World War II disappeared and he became a somewhat older but apparently ageless character, the common fate of long-running fictional heroes. Although his specific age was no longer mentioned, various characters from earlier books occasionally turned up several or even many years later to play important roles in the newer books.
In the first book in the series, Death of a Citizen, which takes place in the summer of 1958, 13 years after the end of the war, Helm is frequently referred to by other characters as being of incipient middle age and apparently soft and out of shape, although no specific age for him is given.
In the next story, which apparently takes place in the summer of 1959, a hostile agent from a rival American spy organization taunts Helm as being a shopworn 36 years old and clearly over the hill as a physical specimen. Later in the book, Helm himself says that he is 36 years old.
A long Internet article by Hayford Peirce examining the issue of Helm's age, however, finds this figure to be improbably young given the information about Helm's background in Death of Citizen. Peirce postulates that Helm was actually several years older than the 36 years mentioned in The Wrecking Crew and that he was probably born around 1918. In the remaining 25 books of the series, however, the age issue vanishes completely.
The well-known critic Anthony Boucher wrote: "Donald Hamilton has brought to the spy novel the authentic hard realism of Dashiell Hammett; and his stories are as compelling, and probably as close to the sordid truth of espionage, as any now being told."  The noted Golden Age mystery writer John Dickson Carr began reviewing books for Ellery Queen's Mystery Magazine in 1969 and, surprisingly, perhaps, often praised thrillers. According to Carr's biographer, "Carr found Donald Hamilton's Matt Helm to be 'my favorite secret agent,'" although Hamilton's books had little in common with Carr's. "The explanation may lie in Carr's comment that in espionage novels he preferred Matt Helm's 'cloud-cuckooland' land. Carr never valued realism in fiction." 
Matt Helm in film and television
A movie series was made in the mid-to-late 1960s starring Dean Martin. The Helm films used the name Matt Helm, his cover identity, several book titles, and some very loose plot elements, but otherwise the series bore no resemblance to the character, atmosphere, or themes of the original books. Likewise, a 1970s TV series, which cast Helm as an ex-spy turned private detective, also departed from the books and was unsuccessful.
In 2002, it was reported that DreamWorks had optioned the entire Helm book series, and in 2005, Variety reported that DreamWorks had signed Michael Brandt and Derek Haas to write a screenplay for a high-six-figure deal. Since then, however, nothing has actually been produced.
(all starring Dean Martin as Helm)
- The Silencers (1966)
- Murderers' Row (1966)
- The Ambushers (1967)
- The Wrecking Crew (1969)
A fifth film was planned, based upon the novel The Ravagers, but Martin declined the opportunity to play the role once more, even though the title of the film was announced at the end of Wrecking Crew.
A 4-DVD box set containing the four films was released in North America in December, 2005.
A television series loosely based upon Hamilton's character was shown by the ABC Network in 1975. Entitled simply Matt Helm, the series starred Anthony Franciosa as a retired spy who becomes a private detective. After being preceded by a pilot TV movie, it ran for only 13 episodes.
- Death of a Citizen (1960)
- The Wrecking Crew (1960)
- The Removers (1961)
- The Silencers (1962)
- Murderers' Row (1962)
- The Ambushers (1963)
- The Shadowers (1964)
- The Ravagers (1964)
- The Devastators (1965)
- The Betrayers (1966)
- The Menacers (1968)
- The Interlopers (1969)
- The Poisoners (1971)
- The Intriguers (1972)
- The Intimidators (1974)
- The Terminators (1975)
- The Retaliators (1976)
- The Terrorizers (1977)
- The Revengers (1982)
- The Annihilators (1983)
- The Infiltrators (1984)
- The Detonators (1985)
- The Vanishers (1986)
- The Demolishers (1987)
- The Frighteners (1989)
- The Threateners (1992)
- The Damagers (1993)
- The Dominators – unpublished. Hamilton finished this novel in the late 1990s, and was reportedly revising it in preparation for seeking a publisher in mid-2002, but as of 2010 it has yet to be published.
- Some Thoughts on Matt Helm's Birthday , an analysis by Hayford Peirce of when Helm was actually born.
- Encyclopedia of Mystery and Detection, by Chris Steinbrunner and Otto Penzler, New York, 1976, page 195.
- John Dickson Carr, The Man Who Explained Miracles, by Douglas G. Greene, New York, 1995, page 443.