John Travolta, of “Grease and “Pulp Fiction” fame, showed up at this year’s Boston Fan Expo.

The actor swung into the annual pop-culture convention on Sunday afternoon, speaking from the show floor’s main stage at the Boston Convention & Exhibition Center in the Seaport.

Travolta’s latest film, “The Fanatic,” had screened at the expo the night before (two weeks ahead of its Aug. 30 release), and his in-person appearance — the actor’s first-ever at a fan convention — was arranged to support it. Welcomed onto the stage by Chuck Berry’s “You Never Can Tell” (in reference to his iconic “Pulp” dance scene with Uma Thurman), Travolta gamely danced up to his seat, showing off the bald look he’s adopted recently. He discussed his lengthy success in Hollywood, as well as the new film, with Canadian media personality Tanner Zipchen.

Reclusive comic-book creator Todd McFarlane, best known for his long-running “Spawn” comics, made a rare public appearance later that afternoon, discussing his work in a smaller-scale fan Q&A. It was his first such Boston engagement in over 20 years.

Famous faces turned out to be plentiful throughout the expo, which ran Friday, Saturday, and Sunday. On hand for all three days were “Shazam!” star Zachary Levi, “iZombie” actress Rose McIver, “Hellboy” creator Mike Mignola, and multiple “Boy Meets World” stars, including Ben Savage, Rider Strong, William Daniels, and Will Friedle.

Along with a who’s who list of comic-book artists and voice actors, some other big names in town at various points included Peter Capaldi (“Doctor Who”), Sean Young (“Blade Runner”), Tyler Hoechlin (“Teen Wolf”), Mike Colter (“Luke Cage”), Laurie Holden (“The Walking Dead”), Jennifer Morrison (“Once Upon a Time”), Stephen Amell (“Arrow”), and Sean Astin, Ke Huy Quan, and Corey Feldman (all reuniting to celebrate “The Goonies”).

Over 50,000 people were said to have attended the expo this year.