There’s something deeply satisfying about a cold, crisp vegetable salad that brings together simplicity, flavor, and nostalgia all in one bite. This Marinated Cucumbers, Onions, and Tomatoes dish reminds me of warm summer days when gardens are bursting with fresh produce, and the kitchen is filled with the tangy aroma of vinegar and herbs. It’s a recipe I reach for when I want something bright, refreshing, and make-ahead friendly — whether I’m preparing for a backyard barbecue or just need a wholesome side to jazz up lunch.

I love how this recipe transforms basic ingredients into a vibrant and addictive salad. The cucumbers stay crunchy, the tomatoes bring sweetness, the onions mellow out in the marinade, and everything gets a kiss of herbs and spices. It’s one of those dishes that only gets better the longer it sits, making it perfect for meal prep or entertaining.

Why You’ll Love This Marinated Cucumbers, Onions, and Tomatoes

This salad is the perfect balance of crisp, juicy, and tangy. You don’t need fancy ingredients or complicated techniques — just a few pantry staples and fresh veggies. It’s gluten-free, naturally vegan, low in calories, and it holds up beautifully in the fridge for several days. Whether you serve it alongside grilled meats, as a light lunch, or as a zesty topping for sandwiches, it adds color and flavor to your plate without weighing you down.

What Kind of Cucumbers Should I Use?

I recommend using English cucumbers or Persian cucumbers for this recipe. They’re seedless (or have very small seeds), have a thin skin, and stay nice and crisp in the marinade. Regular garden cucumbers work too, but I suggest peeling and seeding them first to avoid bitterness and excess wateriness. If you like extra crunch, Persian cucumbers are my top pick.

Cherry or grape tomatoes are ideal since they hold their shape well and don’t release too much liquid, but feel free to use any tomato you love — just cut them into bite-sized pieces.

Options for Substitutions

This marinated salad is super flexible, and here’s how you can make it work for your taste or what’s in your kitchen:

Vinegar: Apple cider vinegar adds a pleasant tang, but white wine vinegar or even red wine vinegar also work beautifully. Avoid balsamic unless you’re aiming for a sweeter flavor.
Sweetener: A small amount of sugar helps balance the acidity. Honey or agave syrup can be used for a natural alternative.
Onions: Yellow, red, or sweet onions all work. Red onions will give a bit more sharpness and color.
Herbs: I typically go with dried Italian herbs or parsley, but dill or basil adds a great twist.
Add-ins: Want more variety? Add thinly sliced bell peppers, a pinch of chili flakes, or even some feta cheese for richness.
Oil: Olive oil is my go-to, but avocado oil or grapeseed oil are good neutral options if you’re looking to change things up.

Ingredients for This Marinated Cucumbers, Onions, and Tomatoes

Cucumbers
The star of the dish. They bring a satisfying crunch and act as the refreshing base that soaks up all the marinade beautifully.
Cherry or Grape Tomatoes
Their sweetness balances the acidity of the vinegar, and their small size makes them perfect for marinating without becoming soggy.
Onions
Thinly sliced onions add sharpness and depth. As they marinate, they soften and mellow, creating a flavorful contrast to the crisp cucumbers.
Vinegar (Apple Cider or White Wine Vinegar)
This brings the necessary tang and brightness. It’s what gives the salad its pickled flavor and helps preserve it in the fridge.
Olive Oil
A little oil balances the acidity and adds a silky texture to the marinade, helping all the flavors blend smoothly.
Sugar
A touch of sugar tones down the sharpness of the vinegar and enhances the natural sweetness of the tomatoes.
Salt & Pepper
Essential for bringing all the flavors to life.
Dried Herbs (Italian seasoning, parsley, or dill)
These give the marinade a herby, aromatic layer that ties everything together.
Red Pepper Flakes (optional)
Just a pinch adds a bit of heat and keeps things exciting.

Step 1: Prep the Vegetables

Start by washing your cucumbers and tomatoes thoroughly. Slice the cucumbers into thin rounds (about ¼ inch thick), halve the cherry tomatoes, and thinly slice the onion. Keep the slices uniform for the best texture and presentation.

Step 2: Mix the Marinade

In a medium bowl or large measuring cup, whisk together the vinegar, olive oil, sugar, salt, pepper, and dried herbs. If you’re using red pepper flakes for a little kick, add them now too. Taste and adjust the seasoning to your preference.

Step 3: Combine Everything

In a large bowl or directly into a glass jar (like a mason jar), layer or mix the cucumbers, tomatoes, and onions. Pour the marinade over the vegetables and toss everything gently to coat. Make sure the veggies are mostly submerged in the marinade — this helps them soak up all the flavor.

Step 4: Marinate

Cover the jar or bowl and refrigerate for at least 2 hours, though it’s best after overnight chilling. The longer it sits, the more the flavors deepen. Give it a shake or stir occasionally to redistribute the marinade.

Step 5: Serve

When you’re ready to serve, give it a final stir. You can spoon it onto plates as a side, scoop it over grilled meat, or even serve it cold straight from the jar. It’s refreshing, tangy, and full of flavor.

How Long to Cook the Marinated Cucumbers, Onions, and Tomatoes

This is a no-cook recipe, which makes it even better during hot months or when you’re short on time. While there’s no actual cooking involved, marinating time is key. Let the vegetables sit in the marinade for at least 2 hours in the refrigerator, but for best results, I recommend marinating them overnight. This gives the cucumbers, onions, and tomatoes plenty of time to soak in all the flavor and reach peak deliciousness.

Tips for Perfect Marinated Cucumbers, Onions, and Tomatoes

Slice Evenly: Uniform slices help the veggies marinate evenly and keep their texture consistent.
Use Fresh Veggies: The fresher your ingredients, the better the flavor and crunch. Avoid overripe tomatoes or soft cucumbers.
Let It Chill Long Enough: Don’t skip the marinating time — the flavors really need time to meld.
Don’t Overcrowd the Jar: If you’re using a jar, don’t pack it too tight. Leave a little space for the marinade to move and coat everything.
Stir or Shake Occasionally: This ensures every piece gets evenly flavored and prevents settling.
Taste Before Serving: After marinating, give it a quick taste and adjust with a little extra vinegar or salt if needed.
Use a Glass Container: Avoid metal or reactive containers as vinegar can react with them — a glass jar or bowl is ideal.

Watch Out for These Mistakes While Cooking

Even though this is a no-cook recipe, a few small missteps can affect the final result:

Skipping the Marinate Time: Rushing the process means you’ll miss out on the deep, tangy flavor that develops with time.
Using Overripe Tomatoes: Soft or overly juicy tomatoes can make the salad mushy and watery.
Too Much Sugar: A little goes a long way — too much can throw off the balance and make it taste more like a pickle dessert than a savory salad.
Over-salting Early On: The flavors intensify as the veggies marinate, so go light on salt at first and adjust later if needed.
Not Using Enough Marinade: Make sure your veggies are well-coated or even partially submerged to soak up the flavor.
Using Dull Knives: Jagged slices can bruise the vegetables and make them less appealing — clean, sharp cuts matter for presentation and texture.

What to Serve With Marinated Cucumbers, Onions, and Tomatoes?

This salad is super versatile and fits into so many meals. Here are some great pairing ideas:

Grilled Chicken

The crisp and tangy salad makes a refreshing contrast to smoky grilled chicken, especially in summer.

Pulled Pork Sandwiches

A spoonful of this salad on the side (or even inside the sandwich) adds brightness and crunch to the richness of pulled pork.

Baked Salmon

The acidity from the vinegar-based marinade cuts through the buttery flavor of baked or grilled salmon perfectly.

Burgers

Serve it alongside a juicy burger as a fresh, tangy side that keeps things balanced.

Roasted Potatoes

Pair it with warm, crispy potatoes for a satisfying hot-and-cold plate full of texture and flavor.

Hummus and Pita

Add this salad to a Mediterranean-style plate with hummus, olives, and warm pita bread.

Fried Catfish

The salad’s acidity cuts right through fried food and adds a refreshing layer to the meal.

Cheese Platter

Serve it as a vinegary, herby counterpoint to rich cheeses like brie, goat cheese, or aged cheddar.

Storage Instructions

One of the best things about this salad is how well it keeps. Store your Marinated Cucumbers, Onions, and Tomatoes in an airtight container or glass jar in the refrigerator. It stays fresh for up to 5 days, and in fact, it often tastes even better after a day or two as the flavors continue to develop. Just make sure the veggies stay submerged in the marinade — give it a stir or a gentle shake daily to keep everything evenly coated.

Avoid freezing this salad — the cucumbers and tomatoes will lose their texture and become mushy once thawed.

Estimated Nutrition (Per Serving – Based on 6 Servings)

Calories: 90
Fat: 6g
Saturated Fat: 1g
Unsaturated Fat: 5g
Cholesterol: 0mg
Sodium: 180mg
Carbohydrates: 9g
Fiber: 2g
Sugar: 5g
Protein: 1g
Serving Size: 1 cup (approx.)

Please note: Nutrition values are approximate and can vary based on specific ingredients and portion sizes used.

Frequently Asked Questions

What type of onion works best for this recipe?

Red onions are my favorite because they add both color and a gentle bite, but you can also use yellow or sweet onions for a milder flavor.

Can I make this salad ahead of time?

Absolutely — in fact, it’s better that way! Make it at least a few hours ahead, or even the day before. The flavor improves the longer it marinates.

Do I need to peel the cucumbers?

Not if you’re using English or Persian cucumbers. For regular garden cucumbers with thick or waxy skin, peeling is a good idea for better texture.

How long will this salad last in the fridge?

Up to 5 days, as long as it’s stored in an airtight container and kept refrigerated. Just give it a gentle stir before serving again.

Can I add other vegetables?

Definitely. Thinly sliced bell peppers, radishes, or even blanched green beans are great additions. Just make sure they’re cut similarly in size to keep the texture balanced.

Is this recipe vegan and gluten-free?

Yes, it’s naturally vegan and gluten-free as written. No changes needed!

Why is there sugar in the marinade?

A small amount of sugar balances the acidity from the vinegar and enhances the natural sweetness of the tomatoes. You can adjust or omit it if needed.

What can I do if the salad is too tangy?

Try adding a bit more olive oil or a small splash of water. A pinch of extra sugar can also help mellow out strong vinegar flavor.

Conclusion

Marinated Cucumbers, Onions, and Tomatoes is one of those timeless dishes that proves simple ingredients can create big flavor. It’s crunchy, tangy, refreshing, and endlessly adaptable — a staple that works just as well on a summer picnic table as it does in a weekday lunchbox. Whether you’re meal prepping or entertaining, this easy side dish adds a vibrant, healthy touch to any meal. Once you try it, I guarantee it’ll earn a regular spot in your fridge.