Combine all ingredients in a blender and blend until smooth.
Pour mixture into a popsicle mold and freeze for 4 - 5 hours. If you chose to use seeded watermelon, strain the mixture through a fine-mesh strainer into a medium bowl and press on the solids to extract as much liquid as possible before pouring into popsicle mold.
Remove from freezer and run molds under water to more easily remove popsicles. Enjoy!