This Marinated Cucumber, Onion and Tomato Salad is a simple old-fashioned side dish made with crisp cucumbers, juicy tomatoes, thinly sliced onions, and a tangy homemade marinade.

The vegetables soak up a sweet-and-vinegary dressing that becomes even more flavorful as the salad chills. It’s refreshing, crunchy, inexpensive, and incredibly easy to prepare.

Serve it alongside grilled chicken, burgers, steak, fried chicken, barbecue, or almost any summer meal.

Why You’ll Love This Salad

Fresh and crunchy
Sweet and tangy
No cooking required
Easy to prepare
Perfect make-ahead side
Great for summer gatherings
Uses simple ingredients
Even better after marinating

Recipe Details

Prep Time: 15 minutes
Marinating Time: 2 hours
Total Time: 2 hours 15 minutes
Servings: 6–8
Course: Side Dish
Cuisine: American

Ingredients

For the Salad

3 large cucumbers
4 medium ripe tomatoes
1 medium yellow or red onion
¼ cup fresh parsley, chopped
2 tablespoons fresh dill, chopped, optional

For the Marinade

½ cup apple cider vinegar
¼ cup vegetable oil or olive oil
2 tablespoons granulated sugar
1 teaspoon salt
½ teaspoon black pepper
½ teaspoon garlic powder
½ teaspoon dried dill
1 teaspoon Dijon mustard, optional

Equipment

You’ll need:

Large mixing bowl
Small bowl or jar
Sharp knife
Cutting board
Whisk
Measuring cups and spoons
Refrigerator-safe container

How to Make Marinated Cucumber, Onion and Tomato Salad

Step 1: Prepare the Cucumbers

Wash the cucumbers thoroughly.

Slice them into thin rounds.

You can leave the skin on for extra color and crunch.

If using large cucumbers with many seeds, cut them in half lengthwise and scoop out some of the seeds before slicing.

This helps prevent the finished salad from becoming too watery.

Step 2: Prepare the Tomatoes

Wash and dry the tomatoes.

Cut them into bite-sized wedges or chunks.

For a prettier salad, use a mixture of red, yellow, or heirloom tomatoes if available.

Avoid cutting the tomatoes too small because they can become soft as they marinate.

Step 3: Slice the Onion

Peel the onion and slice it very thinly.

Separate the slices into individual rings or strips.

Red onion gives the salad a beautiful color, while yellow or sweet onion provides a milder flavor.

If your onion tastes particularly strong, soak the slices in cold water for about 5–10 minutes, then drain thoroughly.

Step 4: Combine the Vegetables

Place the cucumbers, tomatoes, and onions in a large bowl.

Add the chopped parsley and fresh dill if using.

Toss gently.

Be careful not to crush the tomatoes.

Step 5: Make the Marinade

In a small bowl, whisk together:

Apple cider vinegar
Vegetable oil
Sugar
Salt
Black pepper
Garlic powder
Dried dill
Dijon mustard

Whisk until the sugar is mostly dissolved and the marinade is well combined.

You can also place everything in a jar with a tight-fitting lid and shake vigorously.

Step 6: Pour Over the Vegetables

Pour the marinade over the cucumber, onion, and tomato mixture.

Gently toss until all of the vegetables are coated.

Don’t stir too aggressively because the tomatoes can break apart.

Step 7: Refrigerate

Cover the bowl and refrigerate for at least 2 hours.

For the best flavor, allow the salad to marinate for approximately 4 hours.

You can also prepare it the night before.

The vegetables will absorb more of the sweet and tangy marinade as they sit.

Step 8: Stir and Serve

Remove the salad from the refrigerator.

Gently stir before serving.

Taste and add additional salt, pepper, or vinegar if desired.

Serve chilled or slightly cool.

Tips for the Best Cucumber Tomato Salad

Choose Firm Cucumbers

Firm, fresh cucumbers provide the best crunch.

English cucumbers are an excellent choice because they have thin skins and fewer seeds.

Use Ripe but Firm Tomatoes

Very soft tomatoes can become mushy during marinating.

Choose tomatoes that are ripe but still firm.

Slice the Onion Thinly

Thin onion slices distribute their flavor throughout the salad without overpowering the other ingredients.

Don’t Overmix

Gently toss the vegetables to keep the tomatoes intact.

Let It Marinate

Although you can serve the salad immediately, chilling it for a couple of hours gives the dressing time to soak into the vegetables.

Optional Additions

This salad is easy to customize.

Try adding:

Bell peppers
Feta cheese
Avocado
Kalamata olives
Fresh basil
Green onions
Radishes
Mozzarella pearls

For a Mediterranean-style version, add feta, olives, oregano, and extra-virgin olive oil.

Creamy Version

For a creamy variation, replace the oil-and-vinegar marinade with:

½ cup sour cream
¼ cup mayonnaise
1 tablespoon apple cider vinegar
1 teaspoon sugar
½ teaspoon salt
½ teaspoon black pepper
1 teaspoon dried dill

Mix the dressing separately and toss with the vegetables just before serving.

Sweet and Tangy Version

If you enjoy a sweeter salad, increase the sugar to ¼ cup.

For a stronger tang, add another tablespoon of vinegar.

Taste the marinade before adding it to the vegetables and adjust it according to your preference.

What to Serve With It

This refreshing salad pairs beautifully with:

Grilled chicken
Fried chicken
BBQ ribs
Burgers
Grilled steak
Pulled pork
Baked chicken
Grilled fish
Hot dogs
Sausages
Baked potatoes

It’s especially delicious served alongside rich or fried foods because the vinegar-based dressing provides a refreshing contrast.

Make-Ahead Instructions

You can prepare the marinade up to 2 days ahead and store it in the refrigerator.

For the freshest texture, prepare the vegetables several hours before serving.

If making the entire salad the day before, keep in mind that the cucumbers and tomatoes will become softer as they sit.

For maximum crunch, prepare it about 2–6 hours before serving.

Storage

Store leftovers in a covered container in the refrigerator.

For the best texture, enjoy within 2–3 days.

The vegetables will gradually soften as they continue absorbing the marinade.

Always keep the salad refrigerated.

Frequently Asked Questions

Can I use English cucumbers?

Yes. English cucumbers are excellent for this salad because they have thin skins and fewer seeds.

Can I use cherry tomatoes?

Absolutely. Halve them and gently toss them with the other ingredients.

Can I use red onion?

Yes. Red onion adds beautiful color and a slightly sharper flavor.

Can I make this salad overnight?

Yes, although the vegetables will be softer the next day. For maximum crunch, marinate for only a few hours.

Why is my salad watery?

Cucumbers and tomatoes naturally release water. Removing excess cucumber seeds and using firm tomatoes can help. You can also drain some of the liquid before serving.

Can I add cheese?

Yes. Feta cheese, mozzarella pearls, or crumbled goat cheese are excellent additions.

Nutrition Information

Approximate nutrition per serving:

Calories: 120–150
Protein: 2 g
Carbohydrates: 10–12 g
Fat: 8–10 g
Fiber: 2–3 g
Sugar: 6–8 g
Sodium: 300–400 mg

Nutrition will vary depending on the amount of oil, sugar, and vegetables used.

Final Thoughts

This Marinated Cucumber, Onion and Tomato Salad is proof that simple ingredients can make an incredibly flavorful side dish. Crisp cucumbers, juicy tomatoes, and thinly sliced onions soak up a sweet, tangy marinade that makes every bite refreshing.

Marinated Cucumber Onion and Tomato