In the bowl of a stand mixer fitted with a whisk, beat cream cheese, ranch dressing mix, and milk until combined and smooth. Beat in bacon, cheddar cheese, and green onion, just until everything is incorporated.
Spread a heaping tablespoonful of the cream cheese mixture onto each tortilla. Lay 3 or 4 slices of chicken on top and roll tightly. Refrigerate for an hour before slicing and serving.