Cook macaroni in a large pot of salted boiling water until al dente, about 8 minutes. Drain and rinse under cold water until cool.

Fry bacon in a skillet over medium heat until crisp, 6 to 8 minutes. Drain on paper towels and crumble.

Whisk together mayonnaise, sour cream, ranch mix, a pinch of salt, and black pepper in a large bowl until smooth.

Add the cooled macaroni, peas, cheddar, red onion, and half the crumbled bacon. Fold gently until evenly coated.

Transfer to a serving bowl, top with remaining bacon, and serve right away or cover and refrigerate.