Katherine Schwarzenegger's bridal shower receives visit from Oprah

Katherine Schwarzeneggerenjoyed the company of a very special guest at his huge bridal shower blowout … Oprah!!!

On Saturday, Oprah went to Katherine's sumptuous bridal shower, a giant gift box in her hand and a big smile … and the Big O was by far the biggest celebrity in the area.

Katherine's mother, Maria Shriver, organized the party in his private domain … and the crowd was pretty, because Katherine's super celebrities, friends Abby Champion and personality of the television Whitney Harbor, also shown to support the bride.

Oprah and Maria have been friends for decades since they've been working together on a series in the '70s.

It's a bit interesting … Arnold Schwarzenegger and Chris Pratt Katherine's father and fiance were also at his bridal shower.

Arnold has a crazy weekend … he was a proud dad on Saturday morning to his son, Joseph Baenaof college diploma in Malibu.

Katherine and Chris from dating from last summerand in January they announced their engagement.