The 3rd Rock from the Sun star, 52, dished on dating Reynolds in the ’90s during Monday’s episode of Watch What Happens Live.
“It was so long ago I forgot, but literally, so nice, great guy, lovely,” Johnston told host Andy Cohen via video chat.
“Lovely person,” she added.
The pair briefly dated in 1999 and attended the premiere of the Tom Hanks drama, The Green Mile, together.
Reynolds, 43, is now wed to Blake Lively. The pair have been married for seven years and share three daughters: James,