Factual error: The criminologist describes the events of the movie as taking place "on a late November evening". In the very next scene, Brad and Janet are driving in Brad's car, and President Richard Nixon's resignation speech is playing on the radio. Nixon resigned in August of 1974. (00:12:00)
Factual error: During the opening credits, the show's copyright date is shown in Roman numerals as MCLXIV. In Arabic numbers, that's 1164 - it should have been MCMLXIV for 1964.
Factual error: In the scene where Roxie is placed in the "paddy wagon" to be taken to Cook County Jail, the prosecutor refers to himself as District Attorney Harrison. However, the court system in Illinois doesn't have district attorneys; rather, they have state's attorneys. The original play by Maureen Watkins correctly calls him a state's attorney.
Factual error: The sun can't rise out of the Pacific ocean when viewed from America, as seen when Danny is playing the clarinet. (00:01:20)
Factual error: In the scene where Taylor is trying to prove to Gabriella that Troy is a dumb jock who doesn't care about her, Troy is in the locker room with his friends. Troy's friends are recording Troy on a camera attached to a PC, and the image is seen on Taylor's PC. The message on Taylor's PC says an incorrectly spelled 'Recieving WiFi Signal' instead of 'Receiving'. (01:00:55)
Factual error: The Robin that comes along in the movie is an American Robin, not a British Robin.
Factual error: Towards the end of the movie when Ally is in her hallway looking at Jack's old concert tour posters hanging on the wall, the poster closest to the camera says "Washington State Fair" and a 2011 date. Unfortunately, that fair did not get that name until 2013. Before that, it was called "The Puyallup Fair" (officially named the "Western Washington Fair"). Locals still call it "The Puyallup Fair" to this day.
Factual error: At the graduation carnival at the end of the movie, Danny enters wearing a letterman's sweater and explains to his buddies that he earned it by lettering in track. However, on his left sleeve are two stripes, indicating that he lettered in two separate years. Since you are only awarded a stripe for each year you letter, and since Danny was a senior when he lettered in track, his Rydell letterman's sweater should have had only one red stripe on his left arm.
Factual error: In the beginning of the film, the Dowager Empress Marie states that the year is 1916 and that they are celebrating the 300th anniversary of their family's rule. The 300th anniversary actually took place in 1913. (00:01:05)
Factual error: Raoul is the Vicomte de Chagny and he gets called that throughout the movie, even during the auction (which shows he didn't change titles when his parents or his brother died, for example). Yet Christine's tombstone calls her a countess when it should have read viscountess - or, even better, vicomtesse.
Factual error: During the big Newsies rally when Medda is singing "High Times", as she is swinging, lighted exit signs can be seen. I don't believe that those were around in 1899.
Factual error: When Steve Martin dies with the mask on, the inflation bulbs (the little black bags that inflate and deflate) deflate completely. Actually they should INFLATE completely and stay that way. The gas is still on full blast and Steve is no longer inhaling (which would cause them to deflate). It was done only to emphasize Steve Martin's demise but it's factually incorrect.
Factual error: During the orphans' rendition of "You're Never Fully Dressed Without a Smile" Molly is seen with a plastic drink bottle (that makes a plastic-bottle-esque "thunk" when thrown). The movie takes place in 1933, however polyethylene terephthalate (the kind of plastic used for drink bottles) was not developed until 1941.
Factual error: During the press conference, the president says that at 5:00 AM the Baldwin residence was bombed. However, the Baldwins were sunning themselves. And, if the president was referring to Eastern time, it would have been 2:00 AM in Hollywood (sign in the background). (00:26:35 - 00:27:45)
Factual error: After Zidler tells Satine that she is dying, he is seen walking up a stairway past some sewing women. In an overview of the stairs, a stage light to the left has about a dozen or so frosted light bulbs in it. Frosted, tungsten light bulbs were not invented until the mid-to-late 1920s. Any electric light in 1900 would have had clear, carbon-filament bulbs. And no, those are not glass shades over the bulbs.