The Galaxy S21 Ultra isn’t Samsung’s latest flagship anymore, but it’s still an excellent phone. Its design is arguably better than its successor’s, and the top-notch cameras, display, and performance were nearly unparalleled last year, and everything holds up today. The S Pen might not be built-in, but supporting Samsung’s stylus opened up a new world of productivity for Galaxy S customers last year. Whether you bought an S21 Ultra last year and want a new case or just picked one up on sale, we have the best cases you can buy to keep your phone safe.
The Supcase Unicorn Beetle Pro is one of the best cases on the market for extreme protection, and that’s with good reason. The dual-layer construction ensures your S21 Ultra will be safe and sound, and the sturdy kickstand makes media consumption a breeze in landscape or portrait. The case even some with a belt-clip holster for those of you who can’t fit an S21 Ultra in your pocket. Our favorite part of this case is the S Pen holder on the side, making quick note-taking easier than ever. Remember that the S Pen slot adds width to an already wide device. The case is available in Black, Gulden (green), Ruddy (red), Tilt (blue), and Violte (purple).
Supcase Unicorn Beetle Pro for Galaxy S21 Ultra
Cryo Armor uses Air Cushion Technology to keep your phone safe from drops and knocks, but it also keeps your phone cool. Inside the case, there’s a layer of thermally conductive silicone, and the outside of the case has vents that expose this layer to the air. As your phone heats up, this silicone layer will pull some heat away from the phone and vent it out of the back. It might not make a huge difference, but any thermal advantage is welcome during extended gaming sessions, especially now that summer is here.
Spigen Cryo Armor for Galaxy S21 Ultra
![S21 Ultra UAG [U]](https://static0.anpoimages.com/wordpress/wp-content/uploads/2022/06/S21-Ultra-UAG-U.jpg)
The UAG [U] doesn’t look like your average clear case. While most are completely clear, the [U] uses a transparent color combined with a dot pattern on the back to stand out from the pack. Like all UAG cases, the [U] will ensure your phone is safe no matter what you throw at it. There’s a lip raised above the screen and camera module, ensuring your display and lenses stay scratch-free when you put your phone down on a table. The front lip isn’t massive, so if you’re concerned about cracks, we’d recommend combining the case with a screen protector.
The case itself benefits from the same military drop test rating that the rest of UAG’s lineup has, and all of that is wrapped up in an appealing and unique design. You can get the [U] in Ash (dark gray), Orange, Dusty Road, and Ice (light gray).
UAG [U] for Galaxy S21 Ultra
Some need to keep their Galaxy S21 Ultra safe but don’t want a garish case that draws too much attention to itself. The MXX Body Bumper uses a three-layer construction to absorb any impact and prevent it from damaging your phone. Port covers keep dust out of your ports, and a raised bezel prevents your screen from taking damage while leaving room for a screen protector. Many protective cases feature aggressive designs, and while these can look good, many prefer something more understated, and the Body Bumper does just that. There are twelve colors available, with our favorites being Purple/Teal, Red/Gray, and Orange/Gray.
MXX Body Bumper for Galaxy S21 Ultra
Otterbox cases are known for extreme protection at the expense of a bulky design, and the Prefix series turns that on its head. The protection is still top-notch, but the port covers are gone, and the front lip has been shrunk down to keep the case slim. The front lip will still protect your display from scratches, but if you’re concerned about cracks, we’d recommend using a screen protector. The sides of the case are made of a soft TPU that’s comfortable to hold and adds plenty of grip, while the back is made from transparent hard plastic for most of the finishes.
Speaking of finishes, the Prefix comes in five. Black is made from the same soft TPU all around, while the others have a colored TPU frame with a transparent back. The colors available are Black, Clear, Clear/Black, Clear/Blue, and Clear/Red.
Otterbox Prefix series for Galaxy S21 Ultra
If you want a case that lets you leave your wallet behind, the Suanpot Leather Wallet allows just that. The PU leather feels comfortable in hand, and the phone itself sits in a soft TPU enclosure. These two materials should prevent damage from most drops and knocks, with the cover protecting the screen. Inside the case, you’ll find three RFID card slots and a money pouch for cash. The case is available in nine colors: Black, Blue, Blue Green (teal), Light Brown, Purple, Red, Rose Gold, Sea Green, and Wine Red (burgundy).
Suanpot Leather Wallet for Galaxy S21 Ultra
The Presidio2 Grip lives up to its name. The case has ridges that wrap around from the back onto the edges that add grip, making the Presidio2 a difficult case to drop. The whole thing is made from soft-touch plastic, which adds even more grip and makes everything more comfortable to hold. A lip around the front keeps the display scratch-free, and air cushions around the inside of the case frame and on the corners will absorb the kinetic energy from any drops or knocks. The Presidio2 Grip is available in Black, Gray, and Blue.
Speck Presidio2 Grip for Galaxy S21 Ultra
The Caseology Vault is a classy, understated case that keeps your phone safe and feels comfortable to hold. The S21 Ultra is a big phone, so having a slim case like the Vault can be essential if you don’t want to make the phone larger than necessary. Most of the case has a sandstone texture that makes the device harder to drop, while the top third around the camera module switches to a carbon fiber-esque pattern. Despite being a thin case, the Vault still lives up to its name by using shock-absorbing elements built into the case to dissipate kinetic energy. Our one criticism is the lack of color options, as the Vault only comes in Matte Black or Urban Gray.
Caseology Vault for Galaxy S21 Ultra
The S21 Ultra was the first non-Note to support the S Pen, but it came with a significant drawback — nowhere to store the stylus. Spigen’s excellent Liquid Air rectifies this with a “P” version that adds an S Pen silo to the phone’s left side. This case won’t work if you have small hands, adding a lot of width to an already wide phone. But if you’re a hardcore S Pen user, that sacrifice is worth it to have the stylus readily available.
Aside from the S Pen, you benefit from everything that makes the Liquid Air one of our favorite cases. A slim, good-looking design with plenty of grip, and solid protection against drops. Our only criticism is the lack of color options, as it’s only available in black.
Spigen Liquid Air P for Galaxy S21 Ultra
The Cosmo combines two-layer construction, thinness, and top-notch protection in one package. The front layer keeps your screen safe while retaining compatibility with screen protectors, and the back cover surrounds the camera to prevent lens scratches. The back of the case is made from a flexible TPU that’s hard enough to take damage but soft enough to nestle comfortably into your hand. The stand-out feature for the Cosmo is, as always, the striking design. Available in Ameth, Marble, and Ocean, this case isn’t subtle, but each vibrant finish looks good and feels great and ensures your S21 Ultra will stand out in a sea of black and gray cases.
i-Blason Cosmo for Galaxy S21 Ultra
The Otterbox Symmetry is a thick case designed to keep your S21 Ultra safe from anything you throw at it. A thick lip surrounds the display and rear cameras, ensuring both remain scratch-free when you set the device on a table. Covers ensure that your USB-C port is secured against dust and other ingress, and the case features shock absorption to dissipate the kinetic energy from any impact. The Symmetry is available in Black, Blue, Clear, Clear/Pink, and Clear/Silver Flake. If you have the Phantom Silver S21 Ultra, I recommend the Clear/Silver Flake. The transparency allows the phone’s finish to shine through while the flakes add a sparkle as the light catches it.
Otterbox Symmetry for Galaxy S21 Ultra
Keep your phone in tip-top shape
If protection is your primary concern and you don’t mind the added bulk, the Supcase Unicorn Beetle Pro is an excellent choice to keep your S21 Ultra safe from anything you throw at it. Beyond protection, the UBP has helpful additions like a sturdy kickstand that works in landscape and portrait and an S Pen slot that provides quick access to your stylus.
Gamers will appreciate the uniqueness of Spigen’s Cryo Armor, which uses a thermally conductive layer pressed against the S21 Ultra to pull heat away from the device and vent it out of the back. We’re unsure how much of a difference the case will make, but any advantage is welcome in gaming, and the rest of the case is also solid.
The S21 Ultra is a big phone, and a thin case is the best way for many people who don’t want to make it any bigger than necessary. The UAG [U] has a unique design that looks unlike any other cases on this list and can provide the levels of protection you expect from UAG without being a sharp-edged brick of hard plastic.
The Phantom Silver S21 Ultra is one of the best-looking finishes Samsung has put on a phone in recent years, and if that’s the color you have, then you probably want to show it off. The Otterbox Prefix combines a colored soft TPU frame that’s comfortable and protective with a transparent back that shows off that beautiful finish.
