"So much fun hanging out with these boys today #paulrudd @donald_faison and @breckinmeyer! Such a great day at #c2e2," Silverstone captioned a group portrait of her with Meyer, Faison and their cast-mate Paul Rudd, who is not on social media.
"We. Have. No. Clue," quipped Meyer when he posted the same image on Instagram.
"Rollin' with the homies... #clueless #PaulRudd," Faison captioned his Instagram post.
Silverstone also shared on Twitter a picture of her and Rudd, smiling with their cheeks pressed together.
"Such a sweet reunion with my pal Paul Rudd. I love this guy!" she wrote.
The stars played love interests Cher and Josh in the 1995 movie, which was a loose, then-contemporary adaptation of Jane Austen's 1815 novel, Emma. Meyer and Faison played Travis and Murray -- the boyfriends of Cher's best friends Tai and Dionne, played by Brittany Murphy and Stacey Dash.
The romantic comedy followed a group of wealthy teens navigating life and love in Beverly Hills, Calif.
Murphy died of pneumonia in 2009. She was 32.
"I loved playing Cher," UsMagazine.com reported Silverstone told the audience at the Chicago Comic & Entertainment Expo on Saturday. "It was such a fun character and working with these guys -- every one of them was so much fun ... I didn't know who that girl was, so it was really fun to be her. Because it wasn't how I lived my life."