This grilled zucchini and squash is the perfect side dish for summer nights with friends and family. It's a simple recipe that tastes great and has endless options. Zucchini and yellow squash are paired with a marinade that comes together in a snap, then grilled until tender and slightly charred. Serve with fresh herbs, a squeeze of fresh lemon juice, or a little crumble of feta.

Grilled zucchini and squash on a plate with fresh basil leaves and cheese.

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I like to think of this recipe as the summer version of my favorite roasted squash and zucchini recipe.

This version is amazing to serve alongside chimichurri flank steak and a burrata and tomato salad for a crowd-pleasing summertime meal that doesn't involve any cooking indoors.

I top the marinated grilled veggies with extra herbs and cheese (I like feta or goat cheese). but you can try pair with roasted red pepper crema, honey mustard or basil pesto (dairy free).

📖Why My Recipe Works

This recipe, though very simple, is packed with tons of flavor. The marinade is perfectly balanced and complements the zucchini. You don't throw out the excess mariande but add the vegetables back in post-grilling to grab every bit of extra flavor.

But perhaps the most important issue when making grilled vegetables is what the best shape is. I tested three different shapes and several cooking temperatures and times to bring you the best result.

🧾Ingredient Notes

Zucchini and Yellow Squash - Choose medium-to-large zucchini and squash for best results. If you can only find one or the other, use what you're able to get.
Oil - Any high-quality oil will be fine, such as avocado or olive oil.
Dijon Mustard - Mustard has a pungent bite that is delicious against the mild summer squash. Brown mustard or any type of grainy mustard will work but skip the yellow mustard.
Garlic - Use fresh garlic, not garlic powder for the best flavor, you will need one to two cloves.
Dried Thyme - Dried thyme has a lovely, earthy flavor that is amazing with the zucchini. You can use fresh thyme but I found it tended to burn during my recipe testing.
Crushed Red Pepper Flakes - This is optional but I like the little bit of heat.

💭 Seasoning Options

Switch up the marinade to your preference or just try something new - there are endless possibilities for this recipe. Try out some of these combinations.

Blackened: Use my homemade Cajun seasoning and just add the olive oil for a spicy Cajun twist.
Italian: Use an Italian seasoning blend in place of the thyme. Once grilled, top with some grated parmesan cheese and a side of san marzano sauce for dipping.
Chimichurri: Swap out the marinade for my homemade chimichurri or try my creamy chimichurri.
Moroccan: Add harissa paste to the marinade in place of the mustard. Once grilled, top with chopped onions and tomatoes.

How to Cut Zucchini and Squash for Grilling

I tested three different shapes of zucchini - rounds, spears, and planks. The plank shape turned out to be the best for grilling because the shape allows them to be turned easily and doesn't allow them to fall through the grill grates.

Rounds easily fall through the grates, so some type of grill pan is needed. They tend to easily overcook. You could cut them on the bias to make large oval-shaped slices, but then you have a lot of waste with the ends.

For the spears, my biggest issue was the texture. The zucchini spears seem to cook faster than the squash. And the smaller pointed end of the spears got mushy while the spine with the skin wasn't tender enough.

For these reasons- you want to cut your vegetables into flat strips.

Different shapes of zucchini on a plate showing the results of the recipe testing.

⏲️How to Make Grilled Zucchini and Squash

Sliced yellow squash and zucchini, perfect for grilled zucchini and squash recipes, are arranged on a white cutting board beside a knife and a striped kitchen towel.

Trimming the ends off of the zucchini and the squash is optional. Cut them lengthwise into slices about ¼ to ½ inch thick.

Left: A metal bowl with a mixed seasoning paste. Right: Sliced zucchini coated with the seasoning in a glass bowl, ready for grilled zucchini and squash. Both are on a white countertop.

Add the zucchini and squash slices to a mixing bowl and toss with the marinade. It helps to use your hands to ensure all the pieces are fully coated with the oil.

Grilled zucchini and squash halves seasoned with herbs and spices, cooked to perfection on a barbecue grill grate.

Shake off any excess marinade as you place them on. Place the squash and zucchini slices onto a hot grill in a single layer.
It is important that you don't close the lid of the grill. You need to allow the steam to escape, otherwise, you will get mushy veggies.
Serve with the excess marinade and a sprinkle of fresh herbs.

Grilled zucchini and squash on a plate with a dish towel and grilled lemons.

👩🏻‍🍳Jen's Testing Notes

Don't use extra large zucchini. Those are better for shredding into zucchini bread or making zucchini soup.
When grilling the squash, place the slices perpendicular to the grill grates. This will keep them from falling through as well as give them some pretty grill marks.
Be careful when slicing, an even thickness on the vegetable slices will ensure even cooking.

Did you enjoy making this recipe? Show it some love with ⭐⭐⭐⭐⭐ and leave a comment! Hungry for more FLAVORFUL recipes?

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Common Recipe Questions

Do I need to oil the grill grates?

While many recipes have you oil the grill grates, this recipe contains enough oil in the marinade to prevent sticking on well seasoned grates. If your grill is new, I recommend oiling them.

Is it best to peel zucchini before I cook it?

Once cooked, the zucchini is very soft. Without the skin, it can easily fall apart. For this recipe, it's best to use unpeeled squash and zucchini.