Preheat your oven to 375°F. Line a sheet pan with parchment paper or foil.
In a small bowl, mix together the olive oil, garlic, paprika, and salt.
Pat the fish fillets dry with paper towels.
Gently rub each fillet all over with the seasoned oil. Place the fillets, skin side down, on the lined baking sheet. Top each fillet with green onion slices.
Place 2 slices of fresh lemon on top of each fillet.
Place the pan inside the oven and bake the perch until the internal temperature reaches 145°F when checked with a digital thermometer, approximately 15 to 20 minutes.
Serve the cooked perch immediately with lemon wedges on the side.