Brush each ear of corn with olive oil and season with salt and pepper to your liking.
Pour ⅔ cup of water into the slow cooker, then add the seasoned corn and cover with the lid.
Set the slow cooker to high and cook the corn for 3 to 4 hours, or until the kernels are bright yellow and hot.
Once the corn is cooked, add butter to taste and toss to coat each ear evenly.