Preheat your oven to 400°F (200°C).
Wash and cut the baby potatoes in half.
In a large bowl, toss the potatoes with olive oil, salt, and pepper.
Add the sliced smoked sausage to the potatoes.
Sprinkle the ranch seasoning mix over the potatoes and sausage.
Transfer the mixture to a baking sheet in a single layer.
Roast in the preheated oven for about 25-30 minutes.
Remove from the oven and top with shredded cheddar cheese.
Return to the oven and bake for an additional 5-7 minutes until the cheese is melted.
Remove from the oven and sprinkle with sliced green onions.