Bring a large pot of lightly salted water to a boil. Cook elbow macaroni in the boiling water, stirring occasionally until cooked through but firm to the bite, 8 minutes.
Drain macaroni and cool under running water.
Place macaroni into a large salad bowl. Stir in mayonnaise, green peas, tuna, celery, Cheddar cheese, red onion, and chopped sweet pickle until thoroughly combined. Chill and serve.