President Trump has found the next industry he wants to bring back to the U.S. with tariffs: Hollywood.

Trump said in a Truth Social post Sunday that he has authorized a 100% tariff on films produced overseas. He said it was a response to tax incentives in countries such as the United Kingdom and Canada that have lured a substantial number of Hollywood films to shoot outside the U.S.

“​​The Movie Industry in America is DYING a very fast death,” the president wrote. He called international filmmaking incentives “a concerted effort by other Nations and, therefore, a National Security threat. It is, in addition to everything else, messaging and propaganda!”

President Trump has found the next industry he wants to bring back to the U.S. with tariffs: Hollywood.

Trump said in a Truth Social post Sunday that he has authorized a 100% tariff on films produced overseas. He said it was a response to tax incentives in countries such as the United Kingdom and Canada that have lured a substantial number of Hollywood films to shoot outside the U.S.

“​​The Movie Industry in America is DYING a very fast death,” the president wrote. He called international filmmaking incentives “a concerted effort by other Nations and, therefore, a National Security threat. It is, in addition to everything else, messaging and propaganda!”

This year’s highest-grossing film, “A Minecraft Movie,” was shot in Canada. Some of summer’s biggest productions including “Mission: Impossible – The Final Reckoning” and “Jurassic World Rebirth” were also made primarily or entirely outside the U.S.

London in particular has become a thriving hub for Hollywood productions. Disney’s Marvel Studios is shooting a pair of upcoming Avengers sequels there.

Trump said he authorized the Commerce Department and the U.S. Trade Representative to immediately begin the process of instituting a 100% tariff on movies made abroad.

“We’re on it,” U.S. Commerce Secretary Howard Lutnick posted on X Sunday.

It is unclear how such a tariff would work because movies aren’t physical goods that move through ports like most items subject to tariffs. The Trump administration would need to determine how to value a movie in order to apply the tariffs, as well as what the threshold would be to classify it as an import.

If other countries imposed reciprocal tariffs, it could devastate the Hollywood studios, as most big-budget event films earn most of their revenue overseas.

Representatives for the Motion Picture Association of America, the trade group for major Hollywood studios and streaming companies, and the White House didn’t immediately respond to requests for comment.

Trump in January appointed actors Jon Voight, Mel Gibson and Sylvester Stallone as his “special ambassadors” to Hollywood. He said they would help bring back Hollywood business lost to foreign countries.

“These three very talented people will be my eyes and ears, and I will get done what they suggest,” he said.

Write to Ben Fritz at ben.fritz@wsj.com