Scarlett Johansson and Jon Hamm in “The Philadelphia Story,” Hugh Jackman in “On the 20th Century,” Katie Holmes and America Ferrera in “Extremities” — these are among the potential Broadway offerings being explored in recent and upcoming staged readings.

None of these readings rep any kind of guarantee of a star’s attachment to a project or even that the project will move ahead. Still, the possibilities are enticing when Johansson netted a Tony for her Broadway debut in “A View From the Bridge,” Jackman is a proven B.O. powerhouse from stints in “A Steady Rain” and “The Boy From Oz,” and Holmes’ publicity-grabbing stint in a supporting role in “All My Sons” helped keep that show’s grosses healthy.

Johansson, Hamm and John Krasinski were all tapped for a recent reading of “Philadelphia Story” helmed by Alex Timbers (“Bloody Bloody Andrew Jackson”). Philip Barry’s 1939 comedy centers on a socialite whosewedding preparations are complicated by a number of factors, including her ex-husband and a reporter.

It’s said the L.A. reading was under the auspices of the Roundabout Theater Company, which is eyeing a future production, but the org did not comment.

Roundabout is also keeping mum about a recent Jackman-toplined reading of 1978 tuner “On the 20th Century,” the locomotive-set comedy from composer Cy Coleman and book writer-lyricists Betty Comden and Adolph Green. Kristin Chenoweth co-starred in the Roundabout reading; that casting was confirmed in a tweet from fellow thesp Andrea Martin.

Still ahead is a reading of William Mastrosimone’s 1982 drama “Extremities” featuring Holmes, Ferrera, Pablo Schreiber and Kimberly Elise. Drama centers on a woman who turns the tables on her would-be rapist.

Producer Debbie Bisno, who has been developing the revival of the play, confirmed the actors were skedded to be helmed by Kenny Leon in a private table reading but added that no casting or timeline had yet been finalized for a full production.

The readings are just a few of the many attended throughout the year by legit producers, who are always looking ahead to pull together projects that will hit the Main Stem in the coming months or years. As recent seasons have illustrated, star-driven play revivals (such as “The Merchant of Venice” and “Fences”) are among the most reliably profitable of Main Stem outings.