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This cucumber onion salad is light, fresh, and packed with crisp cucumber, tangy red onion, and creamy avocado in a zesty red wine vinaigrette. It is an easy side dish for warm-weather dinners, potlucks, and everyday lunches, and perfect with grilled chicken, fish, shrimp, and more!
Easy Cucumber Red Onion Salad
If ever a salad was cool as a cucumber, it would be this one. Unlike classic cucumber salads, this version gets extra flavor from quick-pickled onions, creamy avocado, and a tangy homemade vinaigrette. Light, flavorful, and incredibly easy to make, this cucumber onion salad is perfect for quick lunches and summer dinners, and easy to customize with fresh herbs, extra veggies, and your favorite cheese.
Here are some other reasons why you’ll love it:
- No cooking required: Just slice, whisk, toss, and serve.
- Prep ahead and assemble later: Make the vinaigrette and onions in advance, then add the cucumber and avocado just before serving.
- Perfect balance of flavors: It’s fresh, tangy, creamy, and crisp all at the same time.
- Easy to serve: Enjoy it as a light lunch or pair it with grilled chicken, fish, shrimp, or sandwiches.
Table of Contents
Ingredients & Substitutions
This cucumber onion salad is made with ingredients tossed in a bright red wine vinegar dressing. A few easy swaps can be made depending on what you have on hand.
For the Salad
- English cucumber: English cucumbers have a mild flavor, crisp texture, and thin skin that doesn’t require peeling. Persian cucumbers will also work. If using standard garden cucumbers, I recommend peeling them first and removing the seeds, especially if they are large.
- Red onions: I love making this salad with pickled red onions because they’re tangier and a little more mellow than regular raw onions. You can buy pre-pickled red onions at the grocery store or make your own quick-pickled red onions in about 30 minutes, then store them in the refrigerator for up to 3 weeks. Of course, thinly sliced raw red onion, sweet onion, or shallot may also be used.
- Avocado: Creamy avocado adds richness and balances the crisp cucumber and tangy dressing. Choose ripe, yet firm avocados so they hold their shape when tossed into the salad and wait to slice and add the avocado until just before serving.
- Cheese: This salad is made with casero cheese, a mild, soft Mexican cheese with a creamy texture and slightly salty flavor. You can find it in the specialty cheese section of most grocery stores. Feta cheese or fresh mozzarella are great substitutes, or omit the cheese entirely for a dairy-free version.
For the Dressing
- Olive oil: Forms the base of the vinaigrette and adds richness. Extra-virgin olive oil works best for flavor, but avocado oil can also be used.
- Red wine vinegar: Adds brightness and acidity to balance the creamy avocado and rich olive oil. White wine vinegar or champagne vinegar are good substitutes.
- Garlic and shallot: Fresh garlic and shallot add savory depth and extra flavor to the dressing. If you don’t have shallot, use a small amount of minced red onion instead.
- Dried oregano, salt, and black pepper: Dried oregano adds subtle Mediterranean-inspired flavor, while salt and black pepper bring everything together. Fresh oregano, dill, or parsley can also be added for extra freshness.
Find the printable recipe with measurements in the recipe card below.
How to Make Cucumber Onion Salad
This cucumber onion salad is super easy to make and looks really pretty when put together. If you’re using quick-pickled onions, I recommend making those first so they have time to soften and soak up all the tangy vinegar flavor. You can make a batch of my Quick Pickled Red Onions ahead of time and keep them in the refrigerator for up to 3 weeks.
- Prepare the pickled onions (optional): Thinly slice the red onion with a mandoline slicer, if you have one, or a sharp knife. Place the sliced onions in a fine mesh strainer, then slowly pour boiling water over the top. This kickstarts the softening, much like blanching would do. Let the water drain completely, then transfer the onions to a medium bowl or jar with rice vinegar and sugar. Stir gently and let them soak for at least 20 to 30 minutes while you prepare the rest of the salad.
- Make the dressing: In a small bowl or jar, whisk together the olive oil, red wine vinegar, garlic, shallot, oregano, salt, and black pepper until fully combined.
- Slice the cucumbers: Thinly slice the cucumbers into rounds about ⅛ to ¼-inch thick, then add them to a large mixing bowl.
- Assemble the salad: Add the pickled onions and sliced avocado to the bowl with the cucumbers. Drizzle with the dressing and gently toss until everything is evenly coated.
- Finish and serve: Top with crumbled casero cheese, feta, or fresh mozzarella. Taste and season with additional salt and black pepper, if needed. Serve immediately for the freshest texture and flavor.
Make-Ahead and Storage Tips
If you’re thinking, “This is way too much work. I just want something I can throw together as soon as I get home from work,” I feel you. Fortunately, this cucumber onion salad is easy to prep ahead, making it perfect for meal prep and busy weeknights.
- Pickle the onions ahead of time: Quick-pickled red onions can be made up to 2 to 3 weeks in advance, just keep them stored in an airtight container in the refrigerator.
- Prepare the dressing early: The vinaigrette can be mixed up to 2 days ahead. Keep it refrigerated and give it a quick whisk or shake before using.
- Slice the cucumbers in advance: Cucumbers can be sliced up to 1 day ahead. Store them in an airtight container lined with a paper towel to absorb excess moisture.
For the best flavor texture, wait to add the avocado and toss everything together just before serving.
Popular Cucumber Salad Variations
There are so many delicious ways to make cucumber salad. Here are a few popular favorites:
- Creamy cucumber salad: Thinly sliced cucumbers tossed with sour cream or Greek yogurt, plus ingredients like red or white onion, shallots, fennel, and fresh dill. Try my creamy cucumber salad for a cool, creamy version that’s perfect for summer.
- Classic cucumber salad: A timeless favorite made with thinly sliced cucumbers, onions, and a simple vinegar-based dressing. Crisp, refreshing, and perfect for picnics, potlucks, and warm-weather meals.
- Asian cucumber salad: Usually made with ingredients like green onion, ginger, garlic, soy sauce, sesame oil, and rice vinegar. Try my Asian cucumber salad for a bold, tangy version packed with flavor.
- Fruity cucumber salad: Add fresh fruit like watermelon, cantaloupe, mango, or strawberries for a sweet and refreshing twist.
- Cucumber tomato salad: Try adding sliced cucumbers to my balsamic tomato basil salad, a summertime staple made with juicy tomatoes, red onion, fresh basil and a light, balsamic vinaigrette.
What’s your favorite cucumber salad recipe?
Frequently Asked Questions
English cucumbers and Persian cucumbers are my top choices because they have thin skin, fewer seeds, and a crisp texture. If using regular garden cucumbers, I recommend peeling them and removing the seeds first, especially if they are large or watery.
Fresh dill, parsley, basil, or mint all work well in this salad. Dill is especially delicious if you want a more classic cucumber salad flavor.
This salad is best enjoyed fresh, but leftovers can be stored in an airtight container in the refrigerator for up to 1 to 2 days. For the best texture, keep the avocado separate and add it just before serving.
No. Pickled onions add extra tanginess and soften the sharp bite of raw onion, but thinly sliced raw red onion works just as well.
This tangy cucumber onion salad pairs well with so many dishes! I love serving it with grilled chicken, shrimp, baked salmon, sandwiches, hamburgers, and just about any Mediterranean-inspired recipe from homemade falafel to Greek chicken souvlaki. It also works nicely as a light lunch or potluck side dish.
More Easy Salad Recipes
If you try making this easy cucumber red onion salad with avocado, I’d love to hear what you think! Please leave a comment and a star rating below, your feedback helps other readers discover (and enjoy) this recipe too. Thank you so much! 💛
Cucumber Onion Salad
Ingredients
For the Pickled Red Onions (optional)
- 2 medium red onions, thinly sliced
- 5 cups boiling water
- 1 cup rice vinegar
- 1 teaspoon sugar
For the Vinaigrette
- 2 tablespoons olive oil
- 4 tablespoons red wine vinegar
- 3 cloves garlic, minced
- 1 shallot, minced
- 1 teaspoon dried oregano
- 1 teaspoon salt
- ½ teaspoon freshly cracked black pepper
For the Salad
- 2 large English cucumbers, sliced into ⅛ to ¼-inch rounds
- 2 avocados, ripe but firm, sliced or chopped
- ½ cup casero cheese, feta cheese, or fresh mozzarella, crumbled or chopped
Instructions
- Prepare the pickled red onions. Thinly slice the red onions using a mandoline slicer or a sharp knife. Place the sliced onions in a fine mesh strainer and slowly pour 5 cups of boiling water over the top to soften their sharp bite. Allow the onions to drain completely.
- Pickle the onions. Transfer the drained onions to a medium bowl or jar. Add 1 cup of rice vinegar and 1 teaspoon sugar, then stir gently to combine. Let the onions sit for at least 20 to 30 minutes while you prepare the rest of the salad.
- Make the vinaigrette. In a small bowl or jar, whisk together 2 tablespoons olive oil, 4 tablespoons red wine vinegar, 3 cloves minced garlic, 1 minced shallot, 1 teaspoon dried oregano, 1 teaspoon salt, and ½ teaspoon freshly cracked black pepper until fully combined.
- Slice the cucumbers. Slice the 2 English cucumbers into rounds about ⅛ to ¼-inch thick and transfer them to a large mixing bowl.
- Assemble the salad. Add the pickled onions and 2 ripe but firm avocados, sliced or chopped, to the bowl with the cucumbers. Pour the prepared vinaigrette over the top and gently toss until evenly coated.
- Finish and serve. Top with ½ cup crumbled casero cheese, feta cheese, or fresh mozzarella. Taste and season with additional salt and black pepper, if needed. Serve immediately for the best texture and flavor.
Notes
- Cucumbers: English cucumbers or Persian cucumbers are best for this salad. If using standard garden cucumbers, peel them first and remove the seeds if they are large.
- Red onions: Pickled red onions add tangy flavor and a softer bite. You can use store-bought pickled red onions, homemade quick-pickled red onions, or thinly sliced raw red onion.
- Avocado: Use ripe but firm avocados so they hold their shape. For the freshest texture and color, add the avocado just before serving.
- Cheese: Casero cheese is mild, creamy, and slightly salty. Feta adds a tangier flavor, while fresh mozzarella keeps the salad softer and more mild. Omit the cheese for a vegan and dairy-free salad.
- Make ahead: The pickled onions can be made up to 2 to 3 weeks in advance and stored in the refrigerator. The vinaigrette can be made up to 2 days ahead.
- Storage: This salad is best enjoyed fresh. Leftovers may be stored in an airtight container in the refrigerator for 1 to 2 days, but the avocado may brown and the cucumbers will soften over time.
- Please checkout the full post for answers to frequently asked questions.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
The pickling solution. Do you throw it out or pour it in with the onions
For your Cucumber Salad, after pickling the red onions, you should drain and discard the pickling solution before adding the onions to the salad. Also shake off any access vinegar. This way, you’ll get the tangy flavor of the onions without the extra liquid, keeping your salad crisp and fresh.
I made the red onion cucumber salad and served it with the Greek marinade chicken and rice. All three recipes from The Forked Spoon. It was a delicious and impressive meal for my friends and family. Thank you.
Thanks for trying all three and leaving such lovely feedback, Marjorie ๐
Hi Jessica
I am going to make the Moroccan stew for my book club dinner. Iโm curious about your choice of serving it with the cucumber red onion salad! I LOVE cucumbers and will probably serve it as well with the stew but just want to know how you came up with that pairing?
Thanks in advance to you answer.