The Hollywood actress appeared in Dracula alongside Reeves, Sir Anthony Hopkins and Gary Oldman in 1992.
Speaking to Entertainment Weekly Ryder said: “We actually got married in Dracula. No, I swear to God I think we’re married in real life.
“In that scene, Francis [Ford Coppola] used a real Romanian priest. We shot the master and he did the whole thing. So I think we’re married.”
The actors have been reunited for a new rom-com called Destination Wedding, which is out later this month.
Ryder reminded Reeves about their vows at a press event for the film, to which he responded “We said yes?”
She said: “Don’t you remember that? It was on Valentine’s Day.”
“Oh my gosh, we’re married,” concluded Reeves.
Ryder has seen huge success in recent years with the Netflix series Stranger Things. The third season is due to air next summer.