Bring a large pot of water to a boil. Add the potatoes and cook until fork tender, about 8 to 10 minutes. Drain and set aside.
While the potatoes are cooked, cook the bacon in a large skillet over medium-high heat until crispy, about 8 minutes. Remove to a paper towel-lined plate to drain. Set aside.
In a large mixing bowl whisk together the mayo, sour cream and mustard until combined and smooth. Add the ranch dressing mix, salt, pepper, onion powder, and paprika. Whisk to combine.
Add the potatoes to the dressing and stir with a wooden spoon until the potatoes are evenly coated in the dressing.
Add almost all of the cheese, bacon, and green onion to the potatoes. (Reserve a little of each to garnish the top of the salad.) Gently mix everything together.
Transfer the potato salad to a serving bowl, and garnish with the reserved cheese, bacon, and green onion.
Serve immediately (if you don't mind a warm potato salad) or cover with plastic wrap and refrigerate until ready to serve.
Notes
I prefer to let my potato salads chill in the fridge to the flavors have more time to marry together. That being said, this salad is great to eat right away too.
If you can't find ranch dressing mix packets at the store, you can substitute 3 tablespoons of my mom's homemade ranch dressing mix.