Place the potatoes in a medium saucepan and add water to cover. Season heavily with salt. Bring to a boil and cook until a paring knife can easily pierce through the center of the potatoes, about 10-15 minutes depending on the size of the potatoes. Drain and let cool completely.
Meanwhile, cook the bacon in a large skillet over medium-high heat until crisp, about 8 minutes. Remove to a paper towel-lined plate to cool. Chop.
Once the potatoes are cooled, cut into bite-size pieces and transfer to a large bowl.
Add the blue cheese dressing, sour cream, celery, green onion, and parsley. Fold in the bacon and season with salt and pepper to taste. Cover and refrigerate until ready to serve.