To help Ed Harris develop the character for Christof, director Peter Weir presented to him a 10 page biography. Part of this biography consisted of Christof doing a film on the homeless for which he won an award.
The couple at the picnic table, Darryl Davis and Robert Davis, are the founders of Seaside, the town where the movie is filmed. Robert Davis inherited the 80 acres from his grandfather, and he and his wife built the first home, and his concept of a small town and mixed-use building has become enormously popular and influential in the last 20 years.
Various trailers included scenes that were deleted from the theatrical and DVD releases: A cast read-through (a sign on the wall warns "ATTENTION: 1. REMOVE CELLPHONES. 2. NO SCRIPTS ON SET. 3. NO I.D. CARDS ON SET"); a visible tear in the "sky" after a stage light falls on the "street" in front of Truman's house; Truman singing the Planet Trumania anthem.
Just before the boat stops, we see the number "139" prominently displayed on its sail. The ensuing dialogue between Truman and Christof contains some paraphrased references to Psalm 139, as do many other aspects of the film.
Director Peter Weir filmed in the 1.66:1 ratio to make it feel more like a television show. Only the original DVD is in this aspect ratio. The theatrical cut was cropped to 1.85:1 and the Blu-ray release to 1.78:1.
The motto on the double archway in the Seahaven town center is UNUS PRO OMNIBUS, OMNES PRO UNO: "One for all, all for one" in Latin, thus fitting the premise of the Truman Show. The motto is also the used in the Alexandre Dumas père's novel, The Three Musketeers.
The State Examination Commission in Ireland listed the film as one of the options for the English comparative study for the Leaving Certificate (state exam taken when leaving school) of 2008 and has just been selected again for 2010.
One of the buildings Truman encounters bears the name "Omnicom". Common beliefs about God centre around the qualities of being omniscient - all-knowing, omnipotent - all-powerful, omnipresent - present everywhere and omni-benevolent - perfect goodness. This alludes to Christof's role as the silent higher power embodying these qualities (except omni-benevolence) in playing God.
Sylvia's apartment contains photos of cast members labeled with Post-It notes. One picture is of Marlon, labeled "Unable to Get Near Marlon - PRIME!". Other photos are labeled "Jogger - 'No Way'" and "will think about it". A printed banner above these photos contains the word "Agents".
The location shoot for Seahaven Island (the film's town in the dome) was in a place called Seaside, Florida. When director Peter Weir arrived there with his pre-production team he said "Unpack our things, we've found our town." The week they arrived during the location scouting is the week they began pre-production.
The name of the "actor" who plays Marlon is listed at the beginning of the film as "Louis Coltrane", an amalgam of the names of the jazz musicians Louis Armstrong and John Coltrane. The character also plays trumpet in the film, another allusion to Armstrong.
The trivia items below may give away important plot points.
According to a 2008 NY Times article, psychologists in Britain and the U.S. reported a number of people experiencing "Truman Syndrome" or "the Truman Show delusion" - the belief that they are the unwitting star of their own reality-TV show. Reportedly, many of those afflicted have specifically mentioned the film while in therapy. More recently, in Sept. 16, 2013, the detailed account of one Ohio student who suffered for years from the Truman-Show delusion is documented in the New Yorker magazine article, "Unreality Star", by Andrew Marantz.
The original script was darker and had crucial differences from the shooting draft. The city was not a utopian society but there were staged criminal incidents. Truman had a drinking problem. It is stated clearly that Truman makes love to his wife (whose real name is Hannah). Christoff's intention was for Truman to have Meryl impregnated and the child would carry on the show. There were more clues that help Truman realize the truth. The scene where Truman confronts Meryl was far more aggressive. Finally and most importantly after Truman passes the door he meets Christoff and the main cast members on a rooftop while in the film the story ends with Truman's exit from the fake world. In the encounter at the rooftop which was in the script the actors stare at him sheepishly but Truman in his rage attacks Christoff and tries to strangle him but the rest of the actors hold him back. He is finally reunited with Sylvia.
Every street name in Seahaven refers to a movie actor, e.g. "Lancaster Square" or "Barrymore Road." All of the "cast" members are likewise named after movie stars - Meryl, Marlon, Lauren, Kirk, Angela, etc.
The events in the movie take place over a 4-5 day time span - Day 10909 to Day 10913 of the show - as shown by the ticker over the TV in the Truman Bar. Truman would have been 6-7 weeks from his 30th birthday. A "30th Anniversary" Truman Show commemorative plate can be seen hanging in the bar.
The ending mirrors the ending of the C.S. Lewis book "Voyage of the Dawn Treader", #4 of the Narnia series (#3 in publication order), with a ship sailing to the end of the "known" world and encountering a sky-blue wall, with a doorway leading to "another" world.