Trivia

Rennie joined the Royal Air Force in 1941, training as a fighter pilot in the US under the Arnold Plan. While at Napier Field in Dothan, AL, for his advanced flight training he was asked by a fellow trainee, Scotsman Jack Morton, what he did in civilian life. Rennie told Morton and the other pilots gathered around that he was a movie actor. They stared at him in disbelief, then broke out in a chorus of laughter. A couple of nights later Rennie and his classmates went into town to watch a movie, Ships with Wings (1941). Not long into the movie, and much to the surprise of those seated with him, Rennie appeared on the screen as Royal Navy pilot Lt. Maxwell.

Lived his final years in Geneva, Switzerland, and died at his mother's home in England while visiting because of his brother's death.

His son with Maggie Rennie, David Rennie (born 1953), is until May 2020 United Kingdom High Court judge on the Lewes, Sussex circuit.

He was connected with the Titanic twice on screen. In 1953 he was the uncredited, off-screen narrator for Jean Negulesco's film Titanic (1953). Thirteen years later he played the role of Capt. Edward J. Smith (misidentified in the credits as Malcolm Smith) in the pilot episode of the television series The Time Tunnel (1966). Interestingly, this episode used tinted stock footage from the earlier film to tell the story of two time travelers who found themselves aboard the doomed ship.

His early career was interrupted by war service. He was a flight instructor for over two of those years.

Had appeared in The 13th Letter (1951) for director Otto Preminger, who later named Rennie as a third party to his counter-suit of adultery against his wife during divorce proceedings in 1958.

Close friends during his 20th Century-Fox years with Tyrone Power and appeared in a few of his pictures, including The Black Rose (1950) and I'll Never Forget You (1951).

Attended and graduated from The Leys School in Cambridge, England. Despite his lean build, he excelled in sports (rowing, fencing, cricket, boxing, wrestling, swimming).

Had a second son, John Marshall Rennie (born 1944), with longtime companion Renee Gilbert Taylor. Professionally, his son went by John M. Taylor.

Son of Edith Amelia (Dobby) and James Alexander Rennie (not the actor James Rennie), who operated a century-old wool mill. His great-great grandfather, named John Rennie, designed and built New London Bridge.

He was cremated after death and his ashes were interred at Harlow Hill Cemetery in Harrogate, North Yorkshire, England.

Did not begin to actively pursue acting until age 29. Living a rather wanderlust life prior to this, he was once a car salesman, but quit after a year when he couldn't sell even one car. Was also a manager of a rope factory for his uncle.

In his best known film, the sci-fi classic The Day the Earth Stood Still (1951), a scene was cut that showed his even-tempered alien character Klaatu in an emotional state.

A heavy smoker, Rennie had respiratory problems for many years. During the run of the Broadway comedy "Mary, Mary" in the early 1960s, he was hospitalized several times; this did not prevent him from being hired to replay his role in the film version, Mary, Mary (1963). His voice was dubbed in The Battle of El Alamein (1969) due to his chronic health problems. Similarly, his own voice is not heard on the English-language dialogue track of his final film, Assignment Terror (1970).

Born on August 25, 1909, the exact same date as Ruby Keeler.