This baked lemon garlic butter tilapia is the sort of weeknight dish that feels both effortless and a little special. I first developed this version on a busy Thursday when I wanted something bright and satisfying that wouldn't keep me away from the table for long. The technique is straightforward: pat the fillets dry, season simply, spoon a butter-forward lemon and garlic mixture over the fish, and roast at a high temperature until the fillets are opaque and flaky. The result is delicate white fish with a glossy, fragrant butter sauce that soaks into every bite.

I discovered how well tilapia responds to quick, hot oven roasting while testing different cooking times for thin fillets. At 425°F for roughly 18 to 20 minutes, the fish keeps moisture without becoming rubbery, and the garlic and lemon bloom without burning. This has become a staple because it tastes restaurant-fresh but uses pantry ingredients, and it’s forgiving—perfect for cooks who want an impressive result with minimal fuss. Serve it over rice, greens, or with crusty bread to sop up the buttery sauce and you’ve got a meal that’s both fast and memorable.

Ingredients

• Tilapia fillets (1 1/2 pounds): Choose firm, fresh or thawed fillets about 4 to 6 ounces each so cook times are even. Look for clean-smelling, glossy flesh; if buying frozen, thaw overnight in the refrigerator and pat dry before cooking.
• Kosher salt (1 1/2 teaspoons): Use coarse kosher salt for even seasoning; measure precisely for balanced flavor — Diamond Crystal or Morton kosher both work, but adjust if using table salt.
• Black pepper or red pepper flakes (1/4 teaspoon): Freshly ground black pepper provides gentle heat; red pepper flakes add a lively kick if you prefer some heat.
• Unsalted butter (4 tablespoons / 1/2 stick): Melted unsalted butter forms the base of the sauce and controls salt level; if you use salted butter, reduce added salt slightly.
• Fresh lemon juice (1 tablespoon): About half a medium lemon — fresher and brighter than bottled juice and critical for that citrus lift.
• Garlic (4 cloves): Finely chopped or minced so it distributes through the sauce and roasts gently without large raw bites.
• Dried thyme (1/2 teaspoon) and paprika (1/2 teaspoon): Thyme adds herbal warmth, while paprika gives color and subtle depth; smoked paprika may be used for a smoky note.
• Garnish — fresh parsley (1 tablespoon, chopped) and lemon wedges: Parsley brightens the finished plate and lemon wedges let diners add extra citrus to taste.

Instructions

Preheat oven and prepare butter mixture: Set the oven to 425°F and position a rack in the center. In a small bowl combine 4 tablespoons melted unsalted butter, 1 tablespoon freshly squeezed lemon juice, 4 cloves finely chopped garlic, 1/2 teaspoon dried thyme, 1/2 teaspoon paprika, and 1/4 teaspoon freshly ground black pepper or red pepper flakes. Whisk until the flavors are fully incorporated — the heat will concentrate them during roasting. Prepare the tilapia fillets: Pat fillets dry with paper towels to remove surface moisture; this encourages even browning and keeps the sauce glossy. Season both sides with 1 1/2 teaspoons kosher salt, then arrange the fillets in an even layer in a 9×13-inch baking dish, allowing a slight overlap only if necessary. If fillets vary greatly in thickness, put thicker pieces at opposite ends so they cook more evenly. Add the lemon garlic butter: Spoon the prepared butter mixture evenly over each fillet, ensuring the garlic is distributed across the surface. Tilt the pan slightly and spoon sauce from the pooling juices over the edges for extra coverage. The melted butter will baste the fish in the oven, keeping it tender and infusing lemon and garlic. Bake the fillets until opaque: Place the dish in the preheated oven and bake for 18 to 20 minutes. The fish is done when it is opaque throughout, flakes easily with a fork, and registers 145°F at the thickest part on an instant-read thermometer. Avoid overcooking — remove from the oven as soon as the flakes separate gently. Garnish and serve: Sprinkle 1 tablespoon coarsely chopped fresh parsley over the hot fillets and serve with lemon wedges. Spoon the buttery juices from the baking dish over each serving. Let the baked fish rest for 2 to 3 minutes before serving so the juices redistribute and plating is tidy.

Storage Tips

To store leftovers, allow the fish to cool at room temperature no more than 30 to 60 minutes, then transfer to an airtight container and refrigerate. Eat within 48 hours for best taste and texture; the butter sauce will firm up in the fridge, so reheat gently in a 300°F oven for 8 to 10 minutes or microwave in 30-second intervals until just warm. For longer storage freeze in a tightly sealed container for up to 3 months. Thaw in the refrigerator overnight and reheat using low, steady heat to avoid drying out the fillets.

Ingredient Substitutions

If tilapia isn’t available, lean white fish such as cod, haddock or sole work well; adjust cooking time for thicker cuts (add 4-6 minutes). Swap unsalted butter for olive oil to make the dish dairy-free — use 3 tablespoons extra-virgin olive oil and finish with a lemon zest for brightness. If you prefer a spicier sauce, increase red pepper flakes to 1/2 teaspoon or add a pinch of cayenne. For herb variation, use fresh thyme instead of dried (use 1 teaspoon fresh) or replace with chopped fresh dill for a Scandinavian twist.

Serving Suggestions

This pairs beautifully with steamed jasmine or brown rice to absorb the buttery sauce, or with lemony roasted potatoes and a green vegetable such as sautéed spinach, asparagus, or a crisp green salad. For a lighter meal serve over a bed of baby arugula with a drizzle of the pan juices and added lemon zest. Garnish with extra chopped parsley and a few cracks of black pepper for contrast. For entertaining, serve family-style with a platter of warm bread and a bright cucumber-dill salad.

Cultural Background

Roasting fish with butter, lemon and garlic is a technique found in many coastal cuisines where simple, fresh ingredients highlight the seafood. The combination leans on classical European practice — particularly Mediterranean and French approaches — where citrus and herbs lift a buttery finish. While tilapia itself is more globally farmed than region-specific, the bright lemon-garlic method echoes coastal traditions of quick roasting and minimal intervention to let the fish’s texture shine.

Seasonal Adaptations

In spring and summer, add a handful of halved cherry tomatoes or capers to the baking dish for an acidic counterpoint and seasonal sweetness. In autumn and winter, complement the dish with roasted root vegetables and swap parsley for hearty chopped flat-leaf parsley or a sprinkle of toasted pine nuts for warmth. For holiday gatherings scale up and bake in two pans to feed a crowd, finishing with a scattering of microgreens for color.

Meal Prep Tips

For meal prep, prepare the butter-lemon mixture and store it in a jar in the refrigerator for up to 3 days. Keep fillets in a covered tray and assemble just before baking to preserve texture. If you’re cooking multiple portions for the week, bake separately sized pans so each reheats evenly. Pack fish in shallow, microwave-safe containers with a wedge of lemon and a small separate container of fresh parsley to add at serving.

Every time I make this, it reminds me of simple dinners where conversation outlasts the meal — it’s easy to prepare, elegant enough for guests, and forgiving when life gets hectic. Try it once and you’ll have a fast, reliable method for cooking delicate fillets that sings with lemon and garlic.