In the 1890s, Lawrence Stevens (Dick Powell) is an obituary writer unhappy in his job, who is given, by a ghostly deceased newspaper man named Pop Benson (John Philliber), a newspaper that has tomorrow's news. He uses the paper to write stories and get the scoop on other reporters; but this also brings him under suspicion by Police Inspector Mulrooney (Edgar Kennedy), who wants to know how Stevens always seems to know what's going to happen and where, mainly a robbery at a theater's box office during a performance. Stevens and his new girlfriend Sylvia (Linda Darnell) – half of a clairvoyant act with her uncle Oscar Smith (Jack Oakie) – have a number of adventures, until her uncle mistakenly thinks that Stevens has consorted with his niece in her boarding house room. The uncle attempts to intimidate Stevens into marrying her, not knowing that Stevens has come to him to ask for her hand.
Stevens gets another newspaper from Pop Benson, intending to use it to pick horses at the racetrack, to win enough money to get married. Unfortunately, he also reads a story about his own death that night, so he and Sylvia get married immediately and head off to the track with her uncle. Stevens bets on winner after winner, amassing $60,000, which is then stolen on their way back to town. They give chase but are arrested for speeding.
Stevens tries his best to avoid the hotel lobby where his death is supposed to take place, but circumstances keep pushing him in that direction. He spots the man who stole his money and chases him on foot through the streets and over the rooftops, until they both fall through the chimney that leads to the very hotel lobby he's been trying to avoid. A gunfight breaks out, and the thief is shot and killed. Because he has Stevens' wallet on him, he is at first identified as the newspaperman, and his newspaper prints an erroneous story saying that their star reporter has been killed. When a reporter finds out the truth, the newspaper has already hit the streets; and it is this edition that Pop had given him.
So Stevens does not die in the hotel lobby, and he and Sylvia live to celebrate their 50th wedding anniversary.
Director and producer Frank Capra originally purchased the rights to Hugh Wedlock and Howard Snyder's story, but when he discovered the concept was similar to that in Lord Dunsany's 20-year-old one act play, he bought it as well; later, when he was going into the Army to serve in World War II, he sold both to Arnold Pressburger. Pressburger approached Rene Clair about directing the film, and the two hired Clair's friend Dudley Nichols to assist in writing the script. They set the time period in the 1890s to avoid dealing with the war.
Clair initially wanted Cary Grant for the lead role, but wound up with Dick Powell, who was on the verge of altering his screen persona from a lightweight musical-comedy "juvenile" to a harder one, playing tough guy private detective Philip Marlowe in Murder My Sweet later that year, followed by a series of film noirs.
Although It Happened Tomorrow was far from Clair's favorite, he was later to write that "[t]he last twenty minutes are the best thing I did in Hollywood." The ending, especially, which hinges on a mistake in the newspaper from the future, had a personal connection for Clair, since he was fired from his first job as a reporter when he made up a story which was the opposite of what actually happened; Nichols was a former newsman as well.
It Happened Tomorrow was a success at the box office. Film historian Jeff Stafford noted that the critical response in the United States was "complimentary but reserved". In France, however, the film was a "major critical success".
It Happened Tomorrow was nominated for two Academy Awards:Best Music, Scoring of a Dramatic or Comedy Picture
Best Sound, Recording (Jack Whitney)
It Happened Tomorrow was adapted as a radio play for the July 3, 1944 episode of Lux Radio Theater with Don Ameche and Anne Baxter, the September 25, 1944 episode of The Screen Guild Theater with Dick Powell and Linda Darnell reprising their original roles and on the October 9, 1946 episode of Academy Award Theater, starring Eddie Bracken and Ann Blyth.