The bun here will definitely have yeast. I've split the list by checking the inside of the burgers etc and listed accordingly.
Some of the burgers contain relish that is made with vinegars. Some research suggests avoiding vinegar. I can tolerate small amounts, it may be that you can as well.
Yeast Free Menu items:
Big Mac Patty and Sauce only- no bun
Big Tasty Patty only - No bun or sauce
Chicken Big Mac Patty and sauce only - no bun
McChicken Sandwich Patty and sauce only - no bun
Quarter & Double Quarter Pounder - no bun
Vegetable Deluxe - no bun
Cheeseburger range - no bun
Mayo Chicken Range - no bun
McNuggets
Veggie Dippers
Shaker Side salad
Bacon Roll range - no bun, just the bacon
Breakfast range Bacon and Egg - no bun or sausage patty!
Pancakes and Syrup only - no Sausage Patty
Porridge range
Hash Browns
Fries
McFlurry range
Happy Meals: McNugget and Veggie Dippers only
Fruit bags
Mixed Berry, Chocolate Brownie and Triple Chocolate Cookie
All drinks and milkshakes
Avoid list:
Big Mac Bun
Sesame Bun
Crispy McFillet
Homestyle Crispy Chicken
McPlant
Chilli Cheese Bites
Fillet-o-Fish
Chicken Legend range
Chicken Selects
Wraps: its in the wrap itself
Chicken Salad range
Breakfast roll range
Muffin with Jam
Cheese and Bacon Flatbread
Happy Meals: Hamburger, Cheeseburger and Fish Fingers
Millionaire's Donut, Sugar Donut and Apple Pie