This marinated cucumber, onion, and tomato salad is a cool, tangy, and colorful side dish that I love making when the weather warms up. It's a classic combo that soaks up a punchy marinade, perfect for picnics, potlucks, or as a refreshing pairing to grilled mains.
Why I Love This Recipe
I love how this salad comes together in minutes with fresh, everyday ingredients. It’s crisp, juicy, and full of that delicious tangy flavor from the marinade. Since it gets better the longer it sits, I like making it ahead of time for easy prep and even better taste. It’s also super versatile and goes with just about anything.
Ingredients
(Here's a tip: Check out the full list of ingredients and measurements in the recipe card below.)
- 3 medium cucumbers, peeled and sliced into ¼-inch rounds
- 3 medium tomatoes, cut into wedges
- 1 medium onion, thinly sliced into rings
- 1 cup water
- ½ cup distilled white vinegar
- ¼ cup vegetable oil
- ¼ cup sugar
- 1 teaspoon salt
- 1 teaspoon freshly ground black pepper
Directions
- In a large bowl, I whisk together the water, vinegar, oil, sugar, salt, and pepper until the sugar dissolves.
- I add the cucumbers, tomatoes, and onion slices to the bowl.
- I gently toss everything together so the vegetables are fully coated in the marinade.
- I cover the bowl and let it chill in the fridge for at least 2 hours, though I like it best when it marinates overnight.
- Before serving, I give it a quick stir to make sure everything is still well coated.
Servings and Timing
- Servings: 6
- Prep time: 15 minutes
- Marinate time: At least 2 hours
- Total time: About 2 hours 15 minutes
Variations
- I sometimes toss in fresh herbs like dill, basil, or parsley to add a burst of freshness.
- If I’m out of white vinegar, I use apple cider vinegar or red wine vinegar for a slightly different flavor.
- To make it less sweet, I reduce the sugar or swap it for honey.
- A pinch of crushed red pepper flakes gives it a gentle heat if I’m craving a little kick.
Storage/Reheating
I keep leftovers in an airtight container in the refrigerator for up to 3 days. The vegetables continue to absorb the marinade, so the flavor deepens, though they do soften a bit. I don’t reheat this salad—it's meant to be served cold and crisp.
FAQs
How long does this salad last in the fridge?
I usually keep it for up to 3 days in the fridge. After that, the veggies lose too much crunch for my taste.
Do I have to peel the cucumbers?
Not at all. I peel them when I want a softer texture, but I also leave the peel on sometimes for a firmer bite and more color.
Can I use a different type of onion?
Yes, I’ve used red onions and sweet onions. Red onions give a sharper bite, while sweet ones mellow out the salad.
Can I make this ahead of time?
Definitely. In fact, I prefer making it the day before serving so the flavors have more time to come together.
What can I serve this with?
I usually serve it with grilled chicken, burgers, or sandwiches. It’s also great next to barbecue dishes or spicy food as a cooling side.
Conclusion
This marinated cucumber, onion, and tomato salad is one of those simple recipes I keep coming back to. It’s quick, refreshing, and always a hit at the table. Whether I’m prepping for a backyard meal or just need a flavorful side in a hurry, this one never disappoints.

Marinated Cucumber, Onion, and Tomato Salad
- Prep Time: 15 minutes
- Cook Time: 0 minutes
- Total Time: 2 hours 15 minutes (including marinating)
- Yield: 6 servings
- Category: Salad
- Method: Marinating (No-Cook)
- Cuisine: American
- Diet: Gluten Free
Description
This marinated cucumber, onion, and tomato salad is a tangy, refreshing summer side dish made with crisp cucumbers, juicy tomatoes, and zesty onions. Perfect for BBQs, potlucks, and picnics, this easy make-ahead salad bursts with flavor thanks to its simple vinegar-based marinade. A quick, healthy, and colorful addition to any warm-weather menu.
Ingredients
- 3 medium cucumbers, peeled and sliced into ¼-inch rounds
- 3 medium tomatoes, cut into wedges
- 1 medium onion, thinly sliced into rings
- 1 cup water
- ½ cup distilled white vinegar
- ¼ cup vegetable oil
- ¼ cup sugar
- 1 teaspoon salt
- 1 teaspoon freshly ground black pepper
Instructions
- In a large bowl, whisk together the water, vinegar, oil, sugar, salt, and pepper until the sugar fully dissolves.
- Add cucumbers, tomatoes, and onion slices to the bowl.
- Gently toss to coat all the vegetables evenly in the marinade.
- Cover and refrigerate for at least 2 hours, preferably overnight for best flavor.
- Stir before serving to redistribute the marinade.
Notes
- Add fresh herbs like dill or parsley for extra brightness.
- Swap white vinegar with apple cider for variation.
- Adjust sweetness by reducing sugar or using honey.
- For a touch of heat, sprinkle in crushed red pepper flakes.
- Salad is best served chilled and gets more flavorful the longer it marinates.