Amazon’s movie strategy is finally ready for its close-up.

After a decade-long dalliance with big-screen theatrical releases, the giant tech company will take center stage this week at the annual convention for theater owners, spending several millions of dollars to parade a stream of A-list stars including Ryan Gosling, Ben Affleck and Chris Hemsworth. It is the first time the company has ever taken on such a role.

The point: to prove that its movie arm, Amazon MGM Studios, is serious about releasing around 14 big, broad commercial films a year to theaters nationwide and around the world.

The appearance is the culmination of a strategic change for Amazon that began when it bought MGM, with the venerable studio’s impressive library, in 2022 for $8.5 billion. For years, the company has released five to eight films theatrically, but it was never clear how long they would stay in theaters before going to Prime Video, Amazon’s streaming service. “Air,” starring Mr. Affleck and Matt Damon, received a 37-day exclusive theatrical release. “Red One,” with Dwayne Johnson and Chris Evans, hit Prime just weeks after it debuted in theaters.

Now with 14 movies a year, Amazon’s lineup will rival those from the big studios in both size and scope, and most will spend 45 days in theaters before hitting pay-per-view and then Prime.

Amazon is making the change in the middle of its own corporate shuffle. Jennifer Salke, who had overseen the film and television operations at Amazon Studios for seven years, abruptly left her job last week, surprising many people inside the company. So when the lights dim at the CinemaCon conference on Wednesday, all eyes will be on Courtenay Valenti, Amazon MGM’s head of film, who will lay out the vision for the company’s theatrical future.

“We have been talking about the theatrical slate and the commitment this company has to theatrical for about two years now,” Ms. Valenti, 61, said in an interview. “Finally, we get to show, not tell.”