Cook penne pasta in a large pot according to package instructions and drain.
Heat olive oil in a large skillet over medium heat.
Add shredded chicken and cook for 2–3 minutes until heated through.
Stir in heavy cream and cream cheese until smooth and creamy.
Add ranch seasoning, salt, and black pepper and mix well.
Add cooked penne pasta to the skillet and toss to combine.
Sprinkle in cheddar cheese and stir until melted.
Simmer for 5–10 minutes until thick and creamy.
Remove from heat and garnish with green onions.
Serve warm and enjoy.