This refreshing marinated cucumber, onion, and tomato salad is crisp, juicy, tangy, and full of fresh flavor. The vegetables are tossed in a simple sweet-and-tangy apple cider vinegar dressing and refrigerated so they have time to absorb all the flavors.

It makes a wonderful side dish for grilled chicken, burgers, steak, fish, sandwiches, or just about any summer meal. It’s also easy to prepare ahead of time, making it perfect for cookouts, family gatherings, and meal prep.

🥗 Recipe Details

Prep Time: 20 minutes
Marinating Time: 1–4 hours
Total Time: About 1 hour 20 minutes
Servings: 6–8
Difficulty: Easy

🛒 Ingredients

For the Vegetables

  • 3 medium cucumbers, thinly sliced
  • 3 large ripe tomatoes, chopped
  • 1 small red onion, thinly sliced
  • 2 tablespoons fresh parsley, finely chopped

For the Marinade

  • ½ cup apple cider vinegar
  • ¼ cup olive oil
  • 2 tablespoons granulated sugar
  • 1 teaspoon salt
  • ½ teaspoon freshly ground black pepper
  • 1 teaspoon dried dill
  • ½ teaspoon garlic powder

👩‍🍳 Detailed Step-by-Step Instructions

1. Prepare the Cucumbers

Wash the cucumbers thoroughly and pat them dry.

You can peel them completely, partially, or leave the skin on. Leaving some or all of the peel gives the salad extra color and texture.

Slice the cucumbers thinly and evenly, approximately ⅛–¼ inch thick.

Tip:

If your cucumbers have a lot of seeds or are particularly watery, you can remove some of the seeds before slicing. This helps prevent the finished salad from becoming excessively watery.

Place the sliced cucumbers into a large mixing bowl.

2. Prepare the Tomatoes

Wash and dry the tomatoes.

Cut them into bite-sized pieces.

If the tomatoes are extremely juicy, you can remove some of the seeds and excess pulp. This isn’t necessary, but it can help the marinade stay more concentrated rather than becoming diluted.

Add the chopped tomatoes to the bowl with the cucumbers.

Best tomatoes to use

For the best flavor, choose tomatoes that are:

  • Ripe
  • Firm
  • Juicy but not overly soft

Roma tomatoes, vine-ripened tomatoes, or garden tomatoes all work well.

3. Slice the Red Onion

Peel the red onion and cut it in half.

Slice it into very thin slices.

Thinly sliced onion absorbs the vinegar dressing much more effectively and develops a milder, sweeter flavor as it marinates.

Add the onion to the cucumbers and tomatoes.

🥣 4. Make the Marinade

In a separate bowl or large measuring cup, combine:

  • ½ cup apple cider vinegar
  • ¼ cup olive oil
  • 2 tablespoons sugar
  • 1 teaspoon salt
  • ½ teaspoon black pepper
  • 1 teaspoon dried dill
  • ½ teaspoon garlic powder

Whisk everything together thoroughly.

Continue whisking until the sugar and seasonings are well distributed throughout the vinegar and oil.

The dressing will naturally separate slightly because it contains both vinegar and oil, so give it another quick whisk immediately before pouring it over the vegetables.

🥗 5. Combine the Vegetables and Marinade

Pour the prepared marinade over the cucumbers, tomatoes, and red onions.

Using salad spoons or two large spoons, gently toss everything together.

Be careful not to stir too aggressively because ripe tomatoes can break apart easily.

Continue tossing until the vegetables are evenly coated with the dressing.

🌿 6. Add the Fresh Parsley

Finely chop the fresh parsley.

Sprinkle it over the salad and gently toss again.

Fresh parsley adds a bright, fresh flavor and gives the salad a beautiful pop of green.

❄️ 7. Refrigerate and Marinate

Cover the bowl tightly with plastic wrap or transfer the salad to an airtight container.

Place it in the refrigerator for at least 1 hour.

For the best flavor, allow it to marinate for approximately 2–4 hours.

During this time, the cucumbers and onions absorb the tangy dressing while the tomatoes release some of their juices into the marinade.

Important:

Give the salad a gentle toss once or twice while it is marinating so the dressing remains evenly distributed.

🍽️ 8. Serve

Remove the salad from the refrigerator shortly before serving.

Give it one final gentle toss.

Taste and adjust the seasoning if necessary.

You can add:

  • A little extra black pepper
  • A pinch of salt
  • More dill
  • A splash of apple cider vinegar
  • Fresh parsley

Serve chilled or slightly cool.

💡 Tips for the Best Marinated Cucumber Salad

Use firm cucumbers

Very soft cucumbers can become mushy during marinating. Fresh, firm cucumbers give you the best crunch.

Don’t slice the cucumbers too thin

Paper-thin cucumber slices can become soft quickly. Aim for approximately ⅛–¼ inch slices.

Use ripe but firm tomatoes

Overripe tomatoes can break apart and make the salad overly watery.

Let it marinate

Although you can eat it after an hour, 2–4 hours gives the flavors more time to develop.

Don’t overmix

Gently toss the salad instead of stirring aggressively. This keeps the tomatoes intact.

🧅 Make the Onions Milder

If you prefer a less sharp onion flavor, place the sliced red onion in a bowl of cold water for 10–15 minutes.

Drain and pat dry before adding the onions to the salad.

This takes some of the sharpness out while allowing the onion to remain crisp.

🍎 Dressing Variations

Less Sweet

If you prefer a more traditional tangy salad, reduce the sugar to:

1 tablespoon

You can also omit it entirely, although the dressing will be noticeably more tart.

More Tangy

For a stronger vinegar flavor, add:

1–2 tablespoons additional apple cider vinegar

Taste before adding more because the vegetables will release liquid as they marinate.

Herb-Loaded Version

For extra freshness, add:

  • 1 tablespoon fresh dill
  • 2 tablespoons fresh parsley
  • 1 tablespoon fresh basil

This creates a beautiful garden-fresh flavor.

🌶️ Spicy Version

For a little heat, add:

  • ¼ teaspoon red pepper flakes
  • A pinch of cayenne
  • 1 finely chopped jalapeño

The spicy flavor works especially well with the sweet-and-tangy marinade.

🧄 Garlic Version

If you’re a garlic lover, replace the garlic powder with:

1–2 fresh garlic cloves, very finely minced.

Fresh garlic gives the dressing a much stronger flavor.

🥒 Additional Vegetables You Can Add

This salad is very customizable.

Try adding:

  • Bell peppers
  • Celery
  • Radishes
  • Green onions
  • Avocado
  • Fresh corn
  • Feta cheese
  • Olives

For a Mediterranean-style version, add feta, Kalamata olives, oregano, and fresh parsley.

🥗 Serving Suggestions

This salad pairs particularly well with:

  • Grilled chicken
  • Chicken patties
  • Turkey burgers
  • Grilled fish
  • Steak
  • BBQ chicken
  • Pulled chicken
  • Sandwiches
  • Wraps
  • Grilled vegetables
  • Baked potatoes

It is especially good served alongside a high-protein meal because the crisp vegetables provide a refreshing contrast to heavier foods.

🧊 Storage

Keep the salad refrigerated in an airtight container.

Because tomatoes and cucumbers release water as they sit, the salad is best enjoyed within 2–3 days.

Give it a gentle toss before serving.

If a lot of liquid accumulates at the bottom, simply drain a little before serving and adjust the seasoning if necessary.

Meal-prep tip

If you’re preparing this specifically for meal prep, consider keeping the tomatoes separate and combining them with the cucumbers and onions closer to serving time. This helps maintain a fresher texture.

⭐ Simple Recipe Summary

Slice: cucumbers, tomatoes, and red onion.

Whisk: apple cider vinegar, olive oil, sugar, salt, pepper, dill, and garlic powder.

Combine: pour the dressing over the vegetables and gently toss.

Marinate: refrigerate for 1–4 hours.

Finish: add fresh parsley, toss gently, and serve chilled.

The result is a crisp, juicy, tangy, slightly sweet vegetable salad that’s simple enough for a weeknight dinner but flavorful enough for a BBQ or family gathering.