The OC actor, 34, proposed to the 27-year-old Gossip Girl starlet last November after less than a year of quietly dating. Adam and Leighton first met while costars on set of The Oranges in 2011, but things didn't turn romantic until later.
And now the twosome, who played Seth Cohen and Blair Waldorf on their respective hit series, got married in a super hush hush wedding. UsWeekly was first to report the news Feb. 18.
The notoriously private pair have yet to comment or confirm the happy news, but Adam was spotted wearing a simple gold wedding band on his left ring finger during a recent trip to the gym.
Leighton took to Twitter to share her happiness about something else besides her wedding: her new role on Broadway in Of Mice and Men.
"So grateful. So excited. Who's comin! Previews start March 19, opening night is April 16," she Instagrammed with a photo of the John Steinbeck script.
Congratulations, you two!