Fill a large pot about ⅔ of the way full with water. Place it onto the stove over high heat and bring the water to a boil.
Add the shrimp to the boiling water and cook until pink and opaque, about 4-5 minutes. (If you want to check to make sure they are done, an internal temperature should read at least 145 degrees F. )
Strain the shrimp and run cold water over them. Then place the shrimp into a large bowl with an ice water bath. Let them sit for at least 10 minutes while you prepare the other ingredients.
In a medium-sized bowl, whisk together the mayo, lemon juice, dijon, lemon zest, dill, garlic powder, Worcestershire sauce, celery salt, salt, pepper, and paprika until smooth. Check the seasoning and adjust the salt and pepper to your taste. Set aside.
Once the shrimp are cold, remove them from the ice bath. Pat the shrimp dry with paper towels as best you can. (You have to make sure the shrimp are dry when adding them to the salad or the dressing will be too watery.) If you want to chop the shrimp into smaller pieces, do that now.
Add the shrimp, celery, red onion, green onion, and parsley to a large bowl, and stir to combine. Add the dressing to the bowl with the shrimp and stir until everything is well coated.
You can serve the shrimp salad immediately or chill it in the fridge until you're ready to eat. We like to put some lettuce on hoagie rolls and then pile on the shrimp salad to make shrimp salad sandwiches
Notes
You should get 2-3 tablespoons of lemon juice from one lemon. So buy one and zest it and juice it for the dressing.
You can use smaller shrimp if desired or chop up the larger shrimp once they're cooked too.
This salad is well-dressed. If you prefer less dressing, cut the dressing part of this recipe in half.
Store any leftovers in the fridge in an airtight container for up to 3 days.