Cook Orzo: Boil the whole wheat orzo according to package instructions. Drain and let it cool.
Prepare Vegetables: While the orzo is cooking, chop the cherry tomatoes, cucumber, red onion, olives, and parsley.
Make Dressing: In a small bowl, whisk together the olive oil, red wine vinegar, Dijon mustard, salt, and pepper.
Combine Ingredients: In a large mixing bowl, combine the cooked orzo, chopped vegetables, and crumbled feta cheese.
Add Dressing: Pour the dressing over the salad and toss gently until everything is well coated.
Chill: Refrigerate the salad for at least 30 minutes to let the flavors meld.