Jon Gosselin is giving marriage another shot … tying the knot with his longtime girlfriend Stephanie Lebo in an intimate Pennsylvania ceremony — with some of his kids there for the big moment.

Sources with direct knowledge tell TMZ … the couple exchanged vows in a low-key ceremony at The Barn at Silverstone in Lancaster, PA — surrounded by 180 loved ones.

Two of Jon’s eight children he shares with ex-wife Kate Gosselin — Hannah and Collin, who are now 21 — were in attendance. Collin was right by his father’s side, serving as one of the groomsmen.

Stephanie’s daughter, Juliana, was also there.

In footage of the wedding captured by ET … Jon was seen looking slick in a gray suit, while Stephanie stunned in a beautiful ball gown. The pair shared a passionate kiss after the officiant said “You may now kiss the bride,” and the crowd erupted.

You’ll recall … Jon was famously married to Kate Gosselin from 1999 to 2008 … with their marriage becoming the centerpiece of the hit reality show “Jon & Kate Plus 8.” In recent years, things have been rocky between them … as they split custody of their sextuplets and two other kids.

As for what’s next … we’re told the newlyweds are planning a Caribbean cruise for their honeymoon next year.