The Guys with Kids actress, 31, is engaged to pro-baseball beau Cutter Dykstra, 23, she announced Monday on her Instagram.
"So this just happened....," she wrote, followed by two hearts and a photo with a shocked looked on her face, showing off her new sparkler alongside her fiancé.
"She said yes!!!" Tweeted Dykstra.
Sigler, who has dated Jets quarterback Mark Sanchez and her former costar Jerry Ferrara, was previously married to A.J. DiScala.
Dykstra, a Washington Nationals infielder, is the son of former New York Mets and Philadelphia Phillies star Lenny Dykstra. Sigler, best known for her role as Meadow on The Sopranos, and Dykstra have been together for about a year after being introduced by another actress/baseball pro pair, Nick and JoAnna Garcia Swisher.