Heat olive oil and 1 tablespoon butter in a skillet. Sauté shrimp until pink and opaque, 2–3 minutes per side. Remove and set aside.
In a separate large skillet or pan, melt 2 tablespoons butter and sauté onions and garlic until fragrant.
Add arborio rice and cook, stirring, for 1–2 minutes until slightly translucent.
Deglaze with white wine and cook until absorbed.
Gradually add warm broth, one ladle at a time, stirring continuously until liquid is absorbed before adding more. Continue until rice is creamy and tender, about 18–20 minutes.
Stir in cooked shrimp, lemon juice, lemon zest, and Parmesan cheese. Adjust seasoning with salt and pepper.