The pair - who played Dawson Leery and Pacey Witter in the series - ran into each other at a party and shared a picture together, reported People magazine.
"The most pleasant run-ins can happen in the most unexpected places..." Van Der Beek wrote on Instagram.
Those hoping for an on-screen reunion are out of luck, as creator Kevin Williamson dismissed the chances of the show returning as a film earlier this year.
The WB teen drama ran from 1998 to 2003 and also starred Katie Holmes and Michelle Williams in the lead roles.