Preheat oven to 400°F (200°C) and grease a 9x13 inch baking dish.
In a large mixing bowl, combine the shredded chicken, condensed cream of chicken soup, ranch dressing, and half of the crumbled bacon.
Spread the chicken mixture evenly into the bottom of the prepared baking dish.
Sprinkle 1 cup of the shredded cheddar cheese over the chicken layer.
Arrange the frozen tater tots in a single, even layer over the cheese.
Bake for 40 minutes or until the tater tots are golden brown and crispy.
Top with the remaining 1 cup of shredded cheddar cheese and the remaining crumbled bacon.
Return to the oven for 5 minutes until the cheese is melted and bubbly.
Garnish with sliced green onions before serving.