In his youth, considered becoming a Catholic priest.
Irish-American.
Liked to drink Irish whiskey at 217 bar in Santa Monica, owned by burlesque great Betty Rowland.
On "The Prisoner" (1967), McGoohan also contributed to the writing and directing of the series.
On June 11, 2008, he became a great-grandfather to Jack Patrick Lockhart.
Owned the rights to an audioclip that metal band Iron Maiden wanted to use in their song "The Prisoner" (1982). He gave them the permission to use it in a telephone conversation with their manager.
Played four different murderers in four different episodes of "Columbo": "Columbo: By Dawn's Early Light (#4.3)" (1974), "Columbo: Identity Crisis (#5.3)" (1975), "Columbo: Agenda for Murder (#9.3)" (1990), and "Columbo: Ashes to Ashes (#13.3)" (1998). He also directed all of them except the first, as well as "Columbo: Last Salute to the Commodore (#5.6)" (1976) and "Columbo: Murder with Too Many Notes (#13.4)" (2000).
Played the same regular character (John Drake) in two different series of Danger Man: "Danger Man" (1960) and "Secret Agent" (1964). His "The Prisoner" (1967) character, Number Six, may also have been intended to be Drake (although McGoohan has always denied this while George Markstein, who co-created the series with McGoohan, continually said he was).
Reprised his "The Prisoner" (1967) character (Number Six) in "The Simpsons" (1989) episode "The Computer Wore Menace Shoes."
Retired from acting after his fourth appearance in "Columbo" in 1998, returning only to provide voice-over work in Treasure Planet (2002).
The son of an Irish-born farmer, he left school at 16 to work in a rope factory. He subsequently worked on a chicken farm but had to seek other employment because of an allergy to chicken feathers.
Turned down two roles that eventually went to Roger Moore: Simon Templar in "The Saint" (1962) and James Bond in Live and Let Die (1973).
Two of his most famous characters, Number Six in "The Prisoner" (1967) and the Warden in Escape from Alcatraz (1979), were not given names.
Used his real birthdate and publicity photo for the character he played ("No. 6") in the TV series "The Prisoner" (1967).
Was a reclusive celebrity, hardly ever giving interviews.
Was the honourary president of Six of One, the official appreciation society for "The Prisoner" (1967), from its foundation in 1977 until his death in 2009.
Was the title character of all four series in which he starred: "Danger Man" (1960) (John Drake), "Secret Agent" (1964) (John Drake), "The Prisoner" (1967) (Number Six), and "Rafferty" (1977) (Dr. Sid Rafferty).
While working as part of Sheffield Repertory, he quickly became one of its leading actors, appearing in more than 200 plays over the following four years. Further repertory work took him to Coventry and Bristol.