Name: Slow Cooker Prime Rib Roast (Tender, Juicy & Foolproof)
Prep time: 20 min
Cook time: 240 min
Total time: 290 min
Ingredients: 5 pound prime rib roast (bone-in or boneless; also called beef ribeye roast or standing rib roast); 5 teaspoons kosher salt (1 teaspoon Diamond Crystal per pound, see notes); 1½-2 teaspoons coarse ground black pepper; 1-2 tablespoons neutral oil (as needed to seare); ½ cup unsalted butter (softened (1 stick)); 10-12 cloves garlic (minced (1 whole head)); 1 tablespoon fresh thyme (minced); 1 tablespoon prepared horseradish; 1 tablespoon Dijon mustard; kosher salt & black pepper (to taste); 1 cup beef stock; 6-8 sprigs fresh thyme

Prime rib has a reputation for being difficult. It's not. It's just expensive, which makes people nervous (understandably!). This Slow Cooker Prime Rib Roast takes the pressure completely off: seared to build a crust, slow-cooked in a garlic herb compound butter, and brought to a perfect finish without you hovering over anything. The compound butter alone is reason enough to make this: a full head of garlic, fresh thyme, Dijon, and horseradish worked into a whole stick of softened butter and slathered all over the beef. The result is incredibly tender, juicy, perfectly medium-rare prime rib with a bold, garlicky herb crust, all with minimal hands-on time and zero oven-babysitting.

Cooked prime rib on plate and with some thin slices cut away from the roast, with creamy horseradish sauce covering the slices.

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Slow Roasted Prime Rib, Stress Free Every Holiday (Crock Pot Method) 🥩

We cook for a living. Which means that by the time the holidays roll around, the last thing we want to do is spend four hours hovering over the oven, thermometer in hand, trying not to ruin a $150 roast in front of company. Oven-roasted prime rib demands a level of attention that's hard to maintain when you're also making sides, setting the table, and trying to have a conversation. The slow cooker is our answer to that.

Cooking prime rib low and slow gives you the most evenly cooked, juicy result you can get at home. The temperature is controlled, the margin for error is essentially zero, and you get your holiday back. Dinner handles itself.

The process is straightforward: season and dry brine overnight, sear to build the crust, slather the whole thing in garlic herb compound butter, then let the crockpot do its thing for a few hours. And if you end up with leftovers (lucky you!), our prime rib sandwich with caramelized onions & arugula is waiting. 😉

🥩 Ingredients for This Slow Cooker Prime Rib Roast

This recipe relies on a handful of pantry staples to build bold flavor on a beautiful cut of beef. The compound butter is where TONS of flavor comes from, don't skip it!

Ingredients to make slow cooker prime rib laid out on a table and labeled to denote each ingredient.

How to Make Slow Roasted Prime Rib in the Crockpot ✨

Don't let the fancy reputation fool you - this comes together in a few straightforward steps. The sear does the heavy lifting up front; the slow cooker takes it from there.

prime rib seasoned with salt and pepper on a white ruffled plate.

Step 1: Season the roast generously on all sides with kosher salt and black pepper. If you have the time, set it uncovered in the fridge for 24 hours. This dry brine lets the seasoning penetrate the meat and crisps up the fat cap beautifully.

🧂 A note on salt: This recipe is made with Diamond Crystal kosher salt, and we use about 1 teaspoon per pound of meat. If using Morton's or table salt, use about half the amount; they're significantly saltier by volume.

💡 Short on time? If you can't dry brine overnight, season at least an hour before cooking, and let the roast come to room temperature before searing. This promotes a more even cook.

prime rib roasting in a cast iron skillet in avocado oil, getting nice and browned on all sides.

Step 2: Heat a large skillet over medium-high heat and add oil. Sear the roast for about 4 minutes on the rib side, then 2-3 minutes on each remaining side until deeply browned all over. Hold it upright with tongs for the sides if needed.

🔥 Don't skip the sear. The slow cooker can't produce the Maillard browning that makes prime rib taste so delicious. Two minutes per side in a hot pan is what gives you that caramelized crust, the slow cooker keeps it tender, and the combo of both is what really makes this roast the best!

stick of butter in a bowl with thyme, salt, dijon mustard, pepper, and minced garlic.

Step 3: While the roast rests briefly after searing, add the softened butter, minced garlic, fresh thyme, horseradish, and Dijon together in a bowl.

compound herb butter mixed together in a bowl.

Mix until it forms a thick, fragrant paste. Season with a bit more salt and pepper.

🧈 The compound butter is the flavor engine of this recipe. A whole head of garlic and a full stick of butter sounds like a lot - it is, and that's the point. It melts into the meat over the long, slow cook and produces the most incredible drippings.

prime rib roast covered in compound butter on a ruffled white plate.

Step 4: Spread the compound butter generously over the top and sides of the seared roast. No need to put it on the bottom.

prime rib covered in garlic herb butter in a slow cooker with braising liquid at the bottom.

Add the beef stock and thyme sprigs to the slow cooker, then place the roast in the slow cooker, rib side down.

💡 Bone-in vs. boneless: Both work great here. Bone-in (standing rib roast) adds a touch more flavor from the marrow and makes for a more impressive table presentation. Boneless is easier to slice and fits better in smaller slow cookers. Either way, go by temperature - not time.

🕐 How long to cook prime rib in the crock pot (on LOW):

4-5 lb roast: approximately 3-4 hours
5-6 lb roast: approximately 3.5-4.5 hours
6-8 lb roast: approximately 4.5-5.5 hours

These are estimates - every slow cooker runs differently, and roast shape affects cook time as much as weight. Always use a meat thermometer. Don't lift the lid to check early; each peek adds 15-20 minutes.

A meat thermometer is non-negotiable on a roast this expensive. Don't guess.

❄️ Temperature guide (pull at 5-8°F below target - the roast will continue to rise as it rests):

Rare: pull at ~120°F (finished ~125-127°F)
Medium-rare: pull at ~125-130°F (finished ~130-135°F) ← our recommendation
Medium: pull at ~135°F (finished ~140-145°F)

Rest before slicing. Transfer to a cutting board, tent loosely with foil, and let rest for 20-30 minutes. This is non-negotiable - it allows the juices to redistribute so every slice is nice and juicy.

Sliced slow cooker prime rib roast on a white scalloped platter with roasted potatoes, fresh thyme, and a glass of red wine.

Step 5: Use a sharp carving knife and slice against the grain. For a bone-in roast, run the knife along the bones first to free them, then slice.

Serve sliced thick with the pan drippings spooned over the top, and a generous spoonful of creamy horseradish sauce on the side. It's a classic pairing for a reason, and making it homemade takes about five minutes.

overhead view of a slow cooker prime rib on a serving platter with fresh thyme, and drizzled with creamy horseradish sauce, surrounded by wine, potatoes, creamed spinach, and more.

This is the kind of meal that feels like a restaurant experience without requiring you to leave your house, and the slow cooker method means you can actually enjoy the event instead of sweating in the kitchen. 🤤

✨ Want a crispier fat cap? Before resting, transfer the roast to a foil-lined baking sheet and broil on high for 3-5 minutes. Watch it closely - the fat cap can go from golden to burnt fast.

What to Serve With Slow Cooker Prime Rib Roast 🍽️

Whether it's Thanksgiving, Christmas, Easter, or any other occasion, the sides are almost just as important as the roast.

Our homemade creamed spinach is perfect. It's rich, garlicky, and deeply savory in a way that belongs on the same plate as prime rib. If you want something heartier, our truffle mashed potatoes or duck fat fondant potatoes are both worthy of a centerpiece roast. For something sweet, try this sweet potato casserole with brown sugar pecans; it rounds out the savory richness beautifully.

And if you're feeding a crowd and want to go all out, our honey pineapple-glazed ham is just as hands-off as this roast. It goes in the oven while the prime rib finishes in the slow cooker. Two impressive centerpieces with minimal extra stress. 😉

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