These Key Lime Pie Overnight Oats are a creamy, sweet, bright, and zesty breakfast inspired by the classic dessert. Key lime overnight oats are a fiber-rich and high protein breakfast, perfect for meal prep!

_{^{This post may contain affiliate links. Thank you for your support!}}

a white ceramic ramekin of key lime pie overnight oats

Recipe Highlights:

These Key Lime Pie Overnight Oats are so delicious, with creamy, sweet, bright and slightly tangy flavors reminding you of the classic key lime pie.

They require minimal prep time and store great in the fridge for a few days, making overnight oats ideal for meal prep and convenient breakfasta.

Plus nutritionally, they’re an absolute powerhouse of a breakfast! One serving has 351 calories, 37 grams of protein, and 8 grams of fiber. Why are protein and fiber so important?

Protein Benefits

Protein is a macronutrient that can make you feel fuller longer. It also promotes health benefits, like:

increasing muscle mass
improving bone density
promoting weight loss
plays an important role supporting your cells, tissues, and organs.

Fiber Benefits

Fiber also promotes many health benefits. One large literature review published in 2020 noted fiber’s benefits include:

improving digestion
decreasing constipation
reducing gut inflammation
lowering cholesterol
reducing the risk of heart disease
reducing diabetes risk
balancing blood sugar
decreasing colon cancer risk
assisting with weight management

Ingredient Notes & Substitutions:

For a full ingredient list with quantities, please check out the recipe card at the bottom of this post.

ingredients to make key lime pie overnight oats

Key Limes – you want to use all of the zest and the juice for max flavor!
Greek Yogurt – adding Greek yogurt is my favorite overnight oats hack to further increase the protein and make them extra creamy. I prefer to use a no added sugar vanilla option for a little extra sweetness, too.
Milk – you can use any milk you prefer to drink. Note that using something like soy, dairy, or an ultra-filtered dairy milk will add additional protein over something like almond milk.
Old-Fashioned Oats – obviously you need oats for overnight oats! I recommend old-fashioned oats. You can use quick oats, but may prefer to use slightly less liquid. I do not recommend steel cut oats for this recipe — the liquid ratios will be too off.
Chia Seeds – chia seeds help create the classic overnight oats texture, while also adding substantial fiber, heart-healthy fats, and a little protein, too.
Flax Seeds – I’m personally a huge fan of adding both chia and flax seeds. Flax also adds more fiber and heart-healthy fats, but you just get a little more nutritional variety with the more plant foods you consume. I recommend using ground flax seeds, as your body will be better able to absorb them.
Protein Powder – While you can omit, I love using protein powder in my overnight oats to majorly boost the protein content and how satiating they are. My favorite to use here is Clean Simple Eats Vanilla Protein Powder — it adds sweetness (from xylitol, stevia, and monk fruit) and the best vanilla flavor I’ve ever found in a protein powder.

How to Make Key Lime Pie Overnight Oats

For complete instructions, please check out the recipe card at the bottom of this post.

mixing wet ingredients to make key lime pie overnight oats

key lime pie overnight oats mixed in a small glass jar

Use a microplane to zest the key lime in its entirety, then juice it. Add the lime juice and zest to a small, 10-ounce glass jar along with the rest of the wet ingredients – the Greek yogurt and milk. Whisk together.

Add in the remaining dry ingredients (oats, chia seeds, flax seeds, and protein powder) and stir to combine. Then seal the lid onto the jar and place in the refrigerator to set overnight, or at least four hours.

Tips and Variations

When zesting your key limes, only zest the green part — don’t zest the white pith underneath. It’s quite bitter!
Switch out the protein powder for a different flavor (like key lime or coconut flavored) — or skip it entirely! If you skip it, you’ll likely want to add some of your preferred sweetener.
Gluten-free: this recipe is naturally gluten-free, so long as you choose a certified-gluten free oats and protein powder.
Dairy-free: Use your favorite dairy-free milk and protein powder, and also use a dairy-free Greek yogurt substitute.
Adjust the texture to your preference before serving. I personally enjoy a thicker overnight oat, but if you prefer them looser, stir in another tablespoon or two of milk before eating.

Meal Prep Storage

Overnight oats are fantastic for meal prep. They’re relatively low maintenance to prep, and store beautifully in the fridge.

I recommend storing overnight oats in individual airtight containers in the refrigerator for for 4-5 days.

Alternatively, they can be frozen up to one month, too.

Do you eat overnight oats cold or hot?

Overnight oats can be consumed hot or cold, it’s entirely your preference. Personally, I enjoy most overnight oats (including these key lime pie overnight oats!) chilled/ straight from the fridge.

If you want them warm, reheat overnight oats in the microwave for 60-90 seconds, or in a pot on the stovetop over medium heat until warmed through.

Shop This Recipe

As an Amazon affiliate, I may earn a small amount from qualifying affiliate purchases at no cost to you.

overhead view of key lime overnight oats garnished with whipped cream and a key lime slice

More Overnight Oats Recipes to Love

Did you make this recipe? Please give a rating and review below! For more balanced nutrition and no fuss, balanced recipes, be sure to follow me on Instagram!