Doohan was born on March 3, 1920, in Vancouver, British Columbia. At 19, after a grueling childhood with an alcoholic father, Doohan left home and joined the Canadian armed forces. After outscoring his fellow soldiers on an officer’s exam, Doohan shot up the ranks from Private to Captain in the Royal Canadian Artillery. On June 6, 1944, Doohan was first off the boat as he led his men into battle on the beaches of Normandy. In the ensuing fight, Doohan was wounded in the leg and hand, and eventually lost a finger. Doohan later returned to active duty after his wounds healed, flying an artillery observation plane for the Royal Canadian Air Force, where he earned the dubious distinction of being the ‘craziest pilot in the Canadian Air Forces’.

After the war, Doohan returned home and found himself looking for the next adventure. Since Doohan served double-duty, he was owed nine years of training and education from the veterans administration. Doohan moved to London, Ontario. While immersed in his studies, he heard the worst radio drama of his life. So frustrated was Doohan with the poor quality of the show that he dropped his books and took up acting. After hearing about a drama school opening in Toronto for veterans, Doohan quickly assembled an audio audition tape and submitted it. Doohan was accepted and subsequently used his newly-discovered vocal talents at a local radio station. He then won a two-year scholarship to the Neighborhood Playhouse in New York City and attended in 1946 alongside such future stars as Leslie Nielsen, Tony Randall and Jackie Gleason.

For the next eight years, Doohan spent time in both New York and his native Canada working on hundreds of radio and television shows, as well as in several movies and plays, thus earning the reputation as Canada’s busiest actor. Though a fine performer, Doohan earned special attention for his distinct vocal talents, particularly his skill with foreign dialects. It was at the behest of director James Goldstone (“Outer Limits”, “Ironside”) that Doohan got the opportunity to read for producer Gene Roddenberry, who was casting for his new science fiction show. In the audition, Doohan presented eight distinct dialects to Roddenberry. When asked which was his favorite, Doohan replied that if life taught him anything, it was that Scotsman made the best engineers.

Though his voice was not his own, Doohan has credited the character of Scotty as being 99% James Doohan and 1% accent. So close was the character to the actor in real life that writers worked in facts of Doohan’s life into the character, such as his love for technical books and gave the engineer the first name "Montgomery," which was Doohan's middle name. Ultimately, “Star Trek” only aired for three seasons—NBC almost canceled in the middle of season two, but fan reaction left the show on for a third and final season. After cancellation, Doohan continued acting, but found that he was hopelessly typecast. To make ends meet, Doohan eked out a living with personal appearances, only to find himself returning to play Scotty in “Star Trek: The Animated Series” (NBC, 1973-74). Doohan then starred as Commander Canarvin in the first season of the live-action Saturday morning “Jason of Star Command” (CBS 1978-81), a children’s series centered around an interplanetary police station.

However much he tried, the lure of Star Trek proved to be too great for Doohan. He returned to his prized role for the first of several movies in “Star Trek: The Motion Picture” (1979). More Star Trek movies were churned out at regular intervals, including “Star Trek II: The Wrath of Kahn” (1982), widely considered to be the best of the lot; “Star Trek IV: The Voyage Home” (1986), a favorite for Doohan for it’s light-hearted comedy; and “Star Trek VI: The Undiscovered Country” (1991), the last motion picture with the ensemble cast. He also reprised the role for "Relics," a memorable 1992 episode of “Star Trek: The Next Generation” (Syndicated, 1987-94) in which the new series' crew discovers Scotty trapped in perpetual stasis in an infinitely looping transporter beam--the ultimate nod to the famed "Trek" catchphrase "Beam me up, Scotty." The engineer is released into a universe years after the one he left behind and finds himself feeling outdated and useless, only to save the day when the new Enterprise is imperiled. It was the beginning of the original cast's formal baton-passing: in 1994, Doohan bid farewell to Scotty in “Star Trek: Generations” with a small role alongside Walter "Chekov" Koenig in the film's opening flashback sequence in the film in which William Shatner starred opposite Patrick Stewart.

The mid-90’s found Doohan’s career winding down, though he did enjoy recurring roles as Damon Warwick on the soap opera "The Bold & the Beautiful" and as Pippen on the "Trek" parody, “Home Boys in Outer Space” (UPN, 1996-97). The latter show was unceremoniously cut from UPN and Doohan slipped into a quieter life. Also in 1996 he penned his memoirs, Beam Me Up, Scotty.

Doohan maintained a schedule of speaking engagements at colleges around the U.S. and Canada, as well as making regular appearances at ever-popular and often fanatic Star Trek conventions. At 80, Doohan had his seventh child with his much-younger third wife, Wende. But throughout his life, Doohan had been afflicted with several health problems, starting with lung fibrosis, which he picked up from chemical exposure during World War II. Doohan was also diagnosed with Parkinson’s Disease, diabetes and most recently, Alzheimer’s. Doohan appeared at his final Star Trek convention at the end of August in 2004, where he was to take the stage with the surviving cast members, including William Shatner and Leonard Nimoy (with whom Doohan had publicly clashed with over the years) for a final farwell and received a star on the Hollywood Walk of Fame. He passed away in July 2005 and his family planned to launch the actor's ashes into space via Houston-based Space Services, which conducts such memorials, in February 2006.