Cook the elbow macaroni in a large pot of salted boiling water according to package directions until al dente.
Drain the pasta and rinse under cold water until completely cooled.
In a large mixing bowl, whisk together the mayonnaise, lemon juice, and Dijon mustard until smooth.
Add the cooled macaroni, cooked shrimp, celery, red onion, and parsley to the bowl.
Toss the ingredients gently until the pasta and shrimp are thoroughly coated in the dressing.
Season with salt, pepper, and smoked paprika.
Cover and refrigerate for at least one hour to allow flavors to meld before serving.