Squash is a good source of potassium. Beans are a good source of potassium. Avocado is high in potassium. Kiwis are packed with potassium, an essential mineral that helps the body maintain proper levels of hydration and electrolytes.Yogurt is high in calcium and potassium.ll of the following foods have potassium values per 1 cup serving greater than 400 milligrams, and many approach 700 milligrams. Root vegetables including potatoes, beets, parsnips, turnips, and rutabagas are the highest in potassium, and are delicious in roasts: a single baked potato with skin has 700 milligrams.