Heat olive oil in a large skillet over medium-high heat.
Season shrimp with 1/2 teaspoon salt and 1/4 teaspoon black pepper.
Add shrimp to the skillet and cook for 2 minutes on each side until pink and opaque. Remove shrimp from skillet and set aside.
In the same skillet, add minced garlic and cook for 30 seconds until fragrant.
Add orzo pasta to the skillet and stir to coat with the garlic and oil.
Pour in chicken broth, lemon zest, lemon juice, remaining 1/2 teaspoon salt, 1/4 teaspoon black pepper, and crushed red pepper flakes.
Bring the mixture to a boil, then reduce heat to medium-low and simmer uncovered for 10 to 12 minutes, stirring occasionally, until the orzo is tender and most of the liquid is absorbed.
Stir in butter until melted and combined.
Return cooked shrimp to the skillet and stir to combine and warm through, about 2 minutes.
Remove from heat and sprinkle with chopped fresh parsley before serving.