This easy and refreshing watermelon cocktail calls for just four simple ingredients and takes almost no time to make! Featuring fresh watermelon juice, fresh lime juice, and light rum, this watermelon rum cocktail is perfect for any summer gathering or occasion. Plus, I’ve included a just as yummy and refreshing mocktail version!

two finished cocktails with watermelon slices next to them

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If you’re searching for the perfect summer cocktail, this recipe is for you! I think there are a few things that scream summer more than fresh watermelon.

There is just something about a cold, juicy watermelon that makes summer feel like, well, summer.

And it’s rare you’ll find any summer event, gathering, or party that doesn’t include watermelon in some way, shape, or form. Honestly, I don’t know why it took me so long to start putting it in cocktails. But man, am I glad I did!

a close up of a watermelon cocktail, you can see part of another cocktail behind it

Not only does watermelon pair perfectly with lime juice and rum, but it’s also the perfect flavor for a quick, easy, and refreshing summer cocktail for any hot day.

This easy cocktail is great for pool parties, brunches, cookouts, the 4th of July, and pretty much any other warm-weather occasion.

Plus, I’ll tell you how to whip up sweet and delicious fresh watermelon juice at home, and as always, I’ve included a just-as-yummy mocktail version so everyone can enjoy this sweet and refreshing drink!

How To Make A Watermelon Rum Cocktail

Mocktail recipe is further down in the post.

Ingredients

For the watermelon juice

a ripe, seedless watermelon. You can use a regular ripe watermelon too, just be sure to remove the seeds before blending!

For the cocktail,

strained fresh watermelon juice
simple syrup, homemade or store-bought
fresh lime juice
white rum, you can also use silver rum or even a coconut rum. Just be sure to use a light rum, as dark rum will change the flavor of the finished cocktail
little watermelon wedges for garnish, optional
ice cubes, for prepping the cocktail

a finished cocktail in front of two watermelon slices

Directions

Chop your watermelon into chunks and place in an upright blender(be sure to set a couple pieces aside to use for a garnish!) and blend on high speed until completely liquified.

Pour the watermelon juice through a fine mesh strainer, discard any pulp or seeds, and set the finished juice aside until ready to use.

Place a few ice cubes into a cocktail shaker, followed by the watermelon juice, lime juice, simple syrup, and rum. Cover tightly and shake roughly for about 30 seconds.

Strain the finished cocktail mixture into two glasses of choice. Garnish with a little watermelon wedge on the rim of each glass and serve immediately.

Enjoy!

Recipe Notes

Since you don’t need a lot of watermelon juice for this recipe, you can blend half or even a quarter of your watermelon and save the rest for fresh eating! Fresh watermelon juice can be stored in the fridge for up to 3 days, but is best consumed within 24 hours. Also, watermelon juice should stay chilled and should not be left sitting at room temperature for longer than 2 hours.

Feel free to add more simple syrup to this cocktail if it isn’t sweet enough for you. You can also sweeten this cocktail with honey or agave nectar instead of simple syrup.

You can find my easy, homemade simple syrup recipe HERE! Simple syrup can be found and bought at most local grocery stores.

a finished cocktail with another cocktail behind it and watermelon slices next to it

How To Make A Watermelon Mocktail

Ingredients

For the watermelon juice

a ripe, seedless watermelon. You can use a regular ripe watermelon too, just be sure to remove the seeds before blending!

For the mocktail

strained fresh watermelon juice
simple syrup, homemade or store-bought. Since there isn’t any alcohol to cut through the sweetness of this drink, I would recommend starting with half the amount of simple syrup, tasting and adjusting if needed.
fresh lime juice
little watermelon wedges for garnish, optional
ice cubes, for prepping the mocktail

Directions

Chop your watermelon into chunks and place in an upright blender(be sure to set a couple pieces aside to use for a garnish!) and blend on high speed until completely liquified.

Pour the watermelon juice through a fine mesh strainer, discard any pulp or seeds, and set the finished juice aside until ready to use.

Place a few ice cubes into a cocktail shaker, followed by the watermelon juice, lime juice, and simple syrup. Cover tightly and shake roughly for about 30 seconds.

Strain the finished mocktail mixture into two glasses of your choice. Garnish with a little watermelon wedge on the rim of each glass and serve immediately.

Enjoy!