Drain the 3 cans (15 ounces each) of whole kernel corn and place the corn in a 6-quart slow cooker.
Add ½ cup milk, 1 tablespoon granulated sugar, 1 teaspoon salt, and ½ teaspoon black pepper. Stir gently to combine.
Place the cubed 8 ounces cream cheese and the sliced ½ cup unsalted butter evenly over the top of the corn mixture. Cover and cook on high for 2-3 hours until the butter and cheese are melted.
Uncover and the stir all the ingredients together.