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The best Samsung Galaxy S21 Ultra thin cases you can buy

If you're going to grab a large phone, you may want a slim case.
The Best
June 1, 2021
Samsung Galaxy S21 Ultra back in hand 5
David Imel / Android Authority

The Samsung Galaxy S21 Ultra is a 6.8-inch beast that’s sure to dominate your pocket space. However, you’ll still have to find a way to keep your new $1,200 device safe from harm. Luckily for you, there are plenty of thin and light ways to do just that. Here are our picks for the best Samsung Galaxy S21 Ultra thin cases you can buy.

See also: Samsung Galaxy S21 buyer’s guide

Looking for more ways to keep your phone safe and get the most out of it? Don’t forget to check out our guide for the best case brands to look at and mobile accessories you can get!

The best Galaxy S21 Ultra thin cases:

Editor’s note: We’ll be sure to add to this list of the best Galaxy S21 Ultra thin cases if new options launch.

Spigen Thin Fit Galaxy S21 Ultra case

thin galaxy s21 ultra spigen thin fit

Spigen is an ever-popular name on our case lists, and it kicks off our slim options with the Thin Fit. While the Thin Fit looks like a simple bumper at first glance, it’s actually a hybrid case that features both polycarbonate and flexible TPU. It’s equipped with Air Cushion technology and raised lips around the display and camera housing, which should help to combat drops. You’ll only find the Spigen Thin Fit for your Galaxy S21 Ultra in matte black.

See also: Spigen cases: A buyer’s guide

Caseology Nano Pop

gs21u caseology nano pop

You’ll find more cases in matte black than you probably care to count, but the Nano Pop is a great way to add a little color to your premium flagship device. It comes in Blueberry Navy and Prune Charcoal, which are two colors you won’t find anywhere else. However, Caseology’s Nano Pop is more than just a colorful thin case. It packs Air Space technology and an internal defense pattern to absorb those harmful impacts.

See also: Caseology cases: A buyer’s guide



If you want an unbelievably thin case then the PHNX MNML Case might just be the perfect case for you. At just 0.35mm thin, you’ll barely even notice that you have a case on your S21 Ultra. The case works with wireless chargers, is branding free and has protective camera cutouts. The PHNX MNML Case sells for $27 and is available in 3 colors, frosted black, white and matte black. Deal: Get 15% off with discount code 15AA at checkout.

Spigen Rugged Armor Galaxy S21 Ultra thin case

thin galaxy s21 ultra spigen rugged armor

We’re back to Spigen for another Galaxy S21 Ultra thin case, and the Rugged Armor is a great TPU option for the money. It’s one of the most affordable cases on the list, and it relies on Spigen’s Air Cushion technology for shock absorption. The Spigen Rugged Armor is yet another matte black case, though the carbon fiber details help to add a premium touch. Like the Thin Fit, Spigen’s Rugged Armor adds a protective lip around both the camera and display.

Speck Presidio2 Grip

gs21u speck presidio2 grip

If you’re prone to dropping your phone, Speck’s Presidio2 Grip might be the best option for you. It features a blanket of raised tactile ridges on the back panel that should help you keep a tight grip. You’ll only find the Presidio2 Grip in matte gray, but the Armor Cloud technology offers impressive protection against tumbles. Speck boasts that its thin Galaxy S21 Ultra case can handle falls from up to 13 feet and a layer of Microban helps to keep germs at bay.

See also: The very best Speck cases you can get

ESR metal kickstand case

thin galaxy s21 ultra esr metal kickstand

When you spend $1,200 on a phone with a 6.8-inch display, you better get the most out of it. One of the best ways to do so is by streaming your favorite shows in the best resolution you can. ESR’s metal kickstand case won’t boost your streaming quality, but it does allow you to binge hands-free. You can choose from a clear finish or a transparent black option, and the kickstand works both vertically and horizontally.

Encased Duraclip with holster

thin sgs21u encased duraclip

The Encased Duraclip is another great way to add a kickstand to your phone, though it’s built a bit differently than ESR’s case. It features a textured plastic kickstand that blends right into the back panel. Encased also includes a belt holster with its Duraclip just in case you can’t fit the Galaxy S21 Ultra in your pocket. Better yet, the belt clip on the holster doubles as yet another kickstand, though it’s better for horizontal content.

Smartish Wallet Slayer

thin galaxy s21 ultra smartish wallet slayer

Thin cases are a great way to save yourself some pocket space, but it also helps to leave your wallet behind. The Smartish Wallet Slayer adds a handy storage slot to the back of your Galaxy S21 Ultra so you can hang onto a few cards or some cash. You can choose from a few different designs, and the highly textured side rails should help you keep a tight grip. Unfortunately, you’ll probably have to take your cards and cash out of the pocket if you want to use wireless charging.

See also: The best phone wallet cases: A buyer’s guide

Ringke Fusion-X Galaxy S21 Ultra thin case

thin sgs21u ringke fusion x

Ringke’s Fusion-X may be the last option on our list, but it’s another popular pick for most devices. It adds a unique geometric bumper for protection against drops and a polycarbonate back panel to handle scratches with ease. You’ll find the traditional clear and camo black versions of the Fusion-X, though Ringke has added a few different options this year including a Ticket Band pattern and a Cross pattern. The Fusion-X features a pair of Quik Catch holes so you can add a lanyard for hands-free carrying.

See also: The best Ringke cases you can buy

Silicone official Galaxy S21 Ultra cover

official galaxy s21 ultra silicone

The thin official case for Samsung’s Galaxy S21 Ultra that you should consider is also one of the simplest. This silicone cover consists of one flexible piece of material and it comes in four different colors to match your new device. It’s not the most durable option on the market, though Samsung’s silicone cover should do well against drops. It also covers a bit of the large camera housing for an even cleaner look.