Red Onion Watermelon salad

Refreshing, low-calorie, full of flavor, and EASY with only 5 easy ingredients…this summer salad checks all the boxes for perfect summer side dish!

This watermelon red onion salads is one of those healthy watermelon recipes that is so fast and easy and GOOD, you won’t believe it. This summer salad is easy for picnics and fast side dishes. The combo of ingredients might sound scary. Be brave, you’ll be so glad you gave it a try.

Watermelon Red Onion Salad is a delightfully refreshing summer salad!

This watermelon salad is an old-school church potluck classic. From “the good ol’ days” of potlucks and sharing dishes.

The name Watermelon Red Onion Salad is a bit scary, don’t you think? But the recipe is light, delicious, and absolutely perfect for summer. This is one of those recipes that kids will look at and be afraid of, adults may be a bit wary, but anyone who is brave enough to try it will immediately be raving and praising you on your genius.

Where did the seeded watermelons go? Honestly, when I head to the store to grab a watermelon there is nothing but seedless versions available. I remember “back in the day” when those seedless versions became the newest thing. Now, I LOOK for the seeded kind. I want to have a day when my 17 year old son cuts into a watermelon and freaks out because there are seeds. Darn kid doesn’t understand how a watermelon SHOULD look because of these seedless versions.

Watermelon Red Onion Salad is a delightfully refreshing summer salad!

Try using a specialty or flavored balsamic vinegar for this recipe. You’ll get an added layer of tasty flavor! My sister’s boyfriend gave me cherry balsamic vinegar that tastes amazing in this recipe!

This salad comes together quickly and with only a few easy ingredients. Watermelon Onion Salad is both sweet and bitter, a perfect side dish for your next gathering or backyard grilling.

Do I have to use balsamic vinegar?

No, absolutely not. I would try a red wine vinegar, instead. I find balsamic to work wonderfully because of the earthy, sweet flavor you find with them.

Can I make this in advance?

Yes, absolutely. However, like any watermelon salad, the longer the watermelon sits in the marinade the more it will seep liquid. You really don’t want to make this salad much more in advance than the morning of.

When serving this for kids, create another bowl without the onions but add the vinegar and sugar. They will love the flavor and being included and you’ll love that you’ve introduced them to a new flavor profile. In fact, maybe you’ll catch one sneaking a bit of your version.

watermelon salad with red onions in it

You don’t have to use red onions for this recipe. Go ahead and try whatever onions you have on hand. However, red onion DOES seem to taste the best and I highly recommend you use it whenever you can.

Serve this salad up alongside grilled burgers & hotdogs, pork chops, or your favorite grilled chicken recipe.

Easy to make, good for you, and great for barbecues!

It’s refreshing and interesting. You won’t eat tons and tons of it, but you will enjoy every bite! Give it a try and be surprised!

Watermelon Salad with Red Onion

| 6 servings
Prep Time | 15 minutes
chilling | 2 hours
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A delightfully refreshing summer salad combine simple ingredients of vinegar, watermelon, and onion in a surprisingly delicious recipe.


  • 1/2 large watermelon cut into large chunks
  • 3 red onions sliced thinly
  • 1/4 cup balsamic vinegar
  • 2 tablespoons sugar
  • 1/4 cup fresh basil, chopped optional
Check out our Kitchen Reference Guide for help with unfamiliar terms.


  • Mix ingredients in bowl.
  • Let sit at room temperature for several hours.
  • Drain off extra liquid.
  • Serve.


Honestly, the measurements on this recipe does not have to be precise. Don’t worry if you don’t have the precise amount of watermelon or onion. Sometimes I add herbs and sometimes I don’t. 
Give this a try and tweak it to your own preferences.


Calories: 160kcalCarbohydrates: 39gProtein: 3gFat: 1gSaturated Fat: 1gSodium: 8mgPotassium: 512mgFiber: 2gSugar: 31gVitamin A: 2187IUVitamin C: 35mgCalcium: 44mgIron: 1mg

So, if you are looking for an easy and healthy addition to your summer salads…give this Watermelon Red Onion salad a try!!

Or if you’re on the search for other delicious salads, try some of these:

Buffalo Chicken Pasta Salad
A yummy pasta salad stuffed with your favorite buffalo chicken flavors in a creamy dressing!
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the BEST Mexican Street Corn Salad
An easy, creamy, full of flavor salad that tastes just like (no…BETTER!) your favorite Mexican Street Corn. A fantastic salad recipe for parties, barbecues, and football games!
Check out this recipe
a scoop of mexican street corn dip
Bacon & Radish Salad
Fast & easy sautéd radishes are a great side dish, easy, and fast!
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Crunchy Pea Salad
This crunchy pea salad is bursting with flavors of Spring and fresh ingredients, that are tossed in a delicious dressing everyone will love. This is quick and easy to make, and you can make it ahead and keep it in the refrigerator ready to serve whenever you need it. This is sure to be a favorite. 
Check out this recipe
Unique & Healthy: Cauliflower potato salad

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