In a medium bowl, combine the rolled oats and chia seeds. Mix well to ensure the chia seeds are evenly distributed.
Pour in the unsweetened non-dairy milk and pure maple syrup. Stir until everything is well combined, and the oats are fully coated in the liquid.
Spoon the mixture into your chosen jar or container. Make sure to leave some space at the top, as the oats will absorb the liquid and expand.
Seal the container tightly and place it in the refrigerator. Let it sit overnight, or at least for 4 hours, so the oats can soften and the flavors meld.
In the morning, give the oats a good stir. You can enjoy them cold or warm them up in the microwave for a minute if you prefer. Top with fresh fruits, nuts, or any of your favorite toppings before digging in!