Meg Ryan Wears Floral Gown and Platform Heels on Academy Museum of Motion Pictures Gala Red Carpet

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Meg Ryan made a rare red carpet appearance for the Academy Museum of Motion Pictures opening gala on Saturday.

At the star-studded event, the When Harry Met Sally star, 59, wore a floor-length, black-and-pink floral gown by Ulyana Sergeenko. She paired the curve-hugging dress with black, open-toed platform heels and simple jewelry and wore her blonde locks in loose waves.

Lady Gaga, Katy Perry, Olivia Rodrigo, Cher, Regina King, Spike Lee and Nicole Kidman were also in attendance to support the new museum, which will have its grand opening for the public on Thursday.

During a preview advance for the museum last week, Tom Hanks — Ryan's frequent movie costar — addressed the press corp in the enormous, sphere-shaped David Geffen Theater building designed by architect Renzo Piano.

"It matters for Los Angeles to have this film museum," said Hanks, 65.

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He continued, "We all know that films are made everywhere in the world, and they are wonderful films. And there are other cities with film museums, but with all due respect in a place like Los Angeles, created by the Motion Picture Academy, this museum has really got to be the Parthenon of such places."

Hanks is a member of the Board of Trustees who, along with actress Annette Bening and former Walt Disney Company CEO Bob Iger, spearheaded fundraising efforts for the project.

"We've been talking about this at the Academy for the better part of, I think, 20 years," he said last Monday. "And the end result exceeds our dreams by about tenfold. It's an extraordinary building. It's an amazing space, it's an inclusive space."

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The museum — which is split between the glass-and-concrete Sphere Building and the Saban Building — houses numerous items from cinematic history.

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The highlights include the Rosebud sled from Orson Welles' Citizen Kane; Star Wars droids C-3P0 and R2-D2; the Mount Rushmore backdrop from Alfred Hitchcock's North by Northwest; the full-sized shark model from Jaws suspended above the escalators; and, as the centerpiece of an expansive display of items from The Wizard of Oz: a pair of Dorothy's ruby slippers.

There is also an assortment of behind-the-scenes artifacts — costumes, hair and makeup, cameras, animation concept art and more — and educational displays on the techniques and evolution behind the filmmaking process.

There are also up-close peeks into the storied history of the Academy Awards including the Oscars Experience, which simulates walking onstage to receive an Oscar.