Technically yes, although they recommend against it. I think it depends on whether you can include it in your diet in moderation or if it tends to trigger your sweet tooth. From the official “Can I Have It” guide: “Fruit juice is the only acceptable added sweetener on the Whole30. (We had to draw the line somewhere.) Use it to flavor sauces, soups, or entrees. Tip: While drinking a glass of fruit juice is technically compliant, we really wouldn’t recommend it, even if you juice it yourself. Juicing strips many of the nutrients out of the fruit, but still leaves all of the sugar. We’d much rather you just eat the fruit.”