Preheat oven to 350 degrees F.
To a medium skillet, melt butter on medium-high heat. Sauté onion and minced garlic until fragrant, about 2-3 minutes. Add in chopped shrimp. Mix to combine. Remove from heat.
In a baking dish, combine spinach (drain first), artichoke hearts, cream cheese, Parmesan, shrimp mixture from skillet, and salt and pepper.
Bake for 15-20 minutes until dip is hot and bubbly. Remove from heat, and top with extra Parmesan, if desired.
Serve with an assortment of veggies, tortilla chips, and/or pita wedges for dipping.