Walnut Grill is a full-service restaurant located in O'Fallon, Missouri. We have a private room that accommodates up to 50 guests and when combining the dining room and the private dining room we can accommodate up to 125 guests. We specialize in Rehearsal Dinners, Bridal Showers, Day after Brunch, and all other types of events which require private space. We offer Buffets & Plated events, including our Casual Affair menu which allows for an appetizer and mingling atmosphere. We are conveniently located on Highway K and Highway 40.