Baked Flounder With Lemon and Butter

Baked flounder with lemon recipe

​The Spruce / Ulyana Verbytska

  • Total: 35 mins
  • Prep: 10 mins
  • Cook: 25 mins
  • Yield: 4 servings
Nutritional Guidelines (per serving)
555 Calories
43g Fat
14g Carbs
29g Protein
See Full Nutritional Guidelines Hide Full Nutritional Guidelines
Nutrition Facts
Servings: 4 servings
Amount per serving
Calories 555
% Daily Value*
Total Fat 43g 55%
Saturated Fat 12g 61%
Cholesterol 137mg 46%
Sodium 875mg 38%
Total Carbohydrate 14g 5%
Dietary Fiber 1g 4%
Protein 29g
Calcium 115mg 9%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

This flavorful baked flounder (or sole) is baked with seasoned lemon butter. This is a very simple recipe, but it doesn't skimp on flavor. Serve it with the optional garlic aioli (below) or serve the fish with a prepared tartar sauce or pesto. 

The recipe can be made with sole, haddock or another mild white fish. Adjust the baking time if the fillets are quite thick. Serve the fish with baked potatoes or rice and a salad or steamed vegetables.


  • 1 1/2 pounds flounder fillets (or sole)
  • 1 teaspoon salt
  • 1/8 teaspoon black pepper
  • 4 tablespoons butter (melted)
  • 2 tablespoons fresh lemon juice
  • 2 teaspoons onion (finely minced)
  • 1 teaspoon paprika (as needed)
  • Garnish: fresh parsley (finely chopped)
  • Garnish: lemon wedges (for serving)
  • Optional Garlic Aioli 
  • 2 medium cloves garlic
  • 1/2 cup mayonnaise
  • 2 tablespoons olive oil
  • 1 tablespoon fresh lemon juice
  • Salt (to taste)

Steps to Make It

  1. Gather the ingredients.

    Ingredients for flounder
    ​The Spruce / Ulyana Verbytska
  2. Butter a shallow baking dish. Preheat the oven to 325 F/165 C/Gas 3.

    Butter pan
    ​The Spruce / Ulyana Verbytska
  3. Cut the flounder fillets into serving-size portions. 

    Cut flounder
    ​The Spruce / Ulyana Verbytska 
  4. Arrange the pieces in the prepared baking dish and sprinkle the fish with 1 teaspoon of salt and the freshly ground black pepper.

    Cut flounder
    ​The Spruce / Ulyana Verbytska
  5. In a small bowl or measuring cup, combine melted butter, 2 tablespoons of lemon juice and minced onion.

    ​The Spruce / Ulyana Verbytska
  6. Pour the lemon-butter mixture over fish.

    Pour over flounder
    ​The Spruce / Ulyana Verbytska
  7. Then, sprinkle the fish with paprika.

    Cover with paprika
    ​The Spruce / Ulyana Verbytska
  8. Bake in the preheated oven for about 20 to 25 minutes or until fish is cooked through and flakes easily with a fork.

    ​The Spruce / Ulyana Verbytska
  9. Garnish with chopped parsley and lemon wedges and serve with garlic aioli (below) if desired.

    ​The Spruce / Ulyana Verbytska
  10. Serve the baked flounder with hot cooked rice or baked potatoes, along with steamed vegetables or a salad.

    ​The Spruce / Ulyana Verbytska

Garlic Aioli

  1. Gather the ingredients.

    Ingredients for aioli
    ​The Spruce / Ulyana Verbytska
  2. Press the garlic into a small bowl and mash well with a fork. Or mash it with a mortar and pestle.

    Press the garlic
    ​The Spruce / Ulyana Verbytska
  3. Add the mayonnaise, olive oil, and lemon juice and whisk to blend thoroughly.

    ​The Spruce / Ulyana Verbytska
  4. Season with salt to taste.

    Add salt
    ​The Spruce / Ulyana Verbytska
  5. Cover and chill until serving time.

    ​The Spruce / Ulyana Verbytska


  • Fish can quickly become tough and dry if overcooked. If the fillets are very thin, check for doneness after about 10 to 15 minutes.