Romo reportedly popped the question while celebrating Candice's 24th birthday on Thursday.
Candice is Chace Crawford's younger sister and she's a sports reporter for KDAF ... the CW station in Dallas which, appropriately, first reported the engagement.
Romo is the second Jessica Simpson ex to put a ring on it recently.
Your move, John Mayer.
UPDATE: Here's a shot of Candice's ring. Well done, Romo. Well done.