Yes, it's time for Blair to tie the knot with Louis... and she's looking rather special in her beautiful dress.
But will she make it down the aisle? Will we have a last-minute objection-in-the-church from Chuck? And why is Georgina Sparks back? (We're so pleased to see deliciously evil Georgina return - hurrah for Michelle Trachtenberg!)
As well as that, we've been promised shocks, surprises and lots of treats for fans. Eek!
Anyway, The CW's released this super-exciting trailer for the episode so give that a watch below, then head on down for a clip of Nate realising he's not too successful in the romance department...
The 100th episode of Gossip Girl, 'G.G.', will air on Monday at 8/7c on The CW.