Bring a large pot of salted water to a boil. Add the orzo and cook according to package directions until al dente. Drain and transfer to a large bowl.
While the orzo is still hot, drizzle 1/2 cup of the olive oil and the lemon juice over it and gently stir to coat; set aside to cool while you cook the shrimp.
Heat the remaining 1/4 cup olive oil in a large skillet over medium-high heat. Add the shrimp in a single layer and cook until they begin to turn pink, about 1–2 minutes per side.
Add the grated garlic to the skillet and cook with the shrimp for 30–60 seconds more, until the shrimp are firm and fully pink. Remove from heat.
Add the cooked shrimp along with any oil and garlic from the skillet into the bowl with the orzo and toss to combine.
Fold in the cucumber, minced red onion, parsley, dill, mint, and cubed feta until evenly distributed.
Taste and season with kosher salt and freshly ground black pepper as desired. Chill before serving if preferred.
