The best Galaxy S21 Ultra case in this 3-way comparison is the Galaxy S21 Ultra Waterproof Case, priced at $41. The Galaxy S21 Plus has its own $41 waterproof match, and the Galaxy S21 has a $31 ring case, so this guide shows the Best Galaxy S21 Ultra, S21 Plus, and S21 case 2026 for your phone.
Gorilla Cases offers Galaxy S21 family cases from our home base in Alliance, Ohio. Use code 10OFF at checkout for 10% off your order.
Why the Right Galaxy S21 Case Matters in 2026
The Galaxy S21 Ultra, Galaxy S21 Plus, and Galaxy S21 are now several years old, and many owners want to keep them going. A good case protects the glass and frame that are left.
The three models look alike but differ in size and camera layout. A Galaxy S21 case will not fit the S21 Plus or S21 Ultra, so a comparison helps.
Older phones deserve fresh protection. Worn edges, aging seals, and tired batteries mean one more drop can be costly.
Gorilla Cases keeps cases for these classic phones in stock. Our Galaxy S21 Ultra case, Galaxy S21 Plus case, and Galaxy S21 case picks are chosen for fit and value.
Galaxy S21 Ultra vs Galaxy S21 Plus vs Galaxy S21: Side by Side
| Phone | Display | Approx. size (mm) | Approx. weight | Gorilla Cases pick | Price |
|---|---|---|---|---|---|
| Galaxy S21 Ultra | 6.8-inch | 165.1 x 75.6 x 8.9 | 227 g | Galaxy S21 Ultra Waterproof Case | $41 |
| Galaxy S21 Plus | 6.7-inch | 161.5 x 75.6 x 7.8 | 202 g | Galaxy S21 Plus Waterproof Case | $41 |
| Galaxy S21 | 6.2-inch | 151.7 x 71.2 x 7.9 | 169 g | Galaxy S21 Ring Case | $31 |
The Ultra is the largest and the only one that supports the S Pen. The Plus is a large phone with a flat display. The Galaxy S21 is the compact option that is easy to hold in one hand.
10 Key Features Across the Three Cases
- Waterproof Ultra case: The S21 Ultra pick is a waterproof case. It suits divers, boaters, and outdoor photographers.
- Waterproof Plus case: The S21 Plus pick is also waterproof. It fits the 6.7-inch Galaxy S21 Plus.
- Ring case for the S21: The Galaxy S21 pick is a ring case with a car-friendly design. It helps with one-handed use.
- Model-matched fit: Each case is made for one phone. Buttons and cutouts line up.
- Color options: The Galaxy S21 Ring Case comes in black, blue, and red. The waterproof cases list black.
- Equal Ultra and Plus pricing: Both waterproof cases are $41. Choose by phone size.
- Budget ring case: The Galaxy S21 Ring Case is $31. It is the lowest-priced pick.
- Wider selection: The S21 Ultra collection holds 26 products. You can browse wallets, metal cases, and screen protectors.
- Screen add-ons: A Galaxy S21 Ultra screen protector and camera lens pack is also available. It adds glass protection.
- Easy returns: Every order has a 30-day exchange policy. That lowers the risk of ordering the wrong fit.
Which Galaxy S21 Case Is for You
Choose the Galaxy S21 Ultra case if you want waterproof protection for the largest phone. Choose the Galaxy S21 Plus case for the same waterproof approach on the mid-size model. Choose the Galaxy S21 case if you want a simple, low-cost ring case.
Here are the direct picks. For the Plus, see the Galaxy S21 Plus Waterproof Case. For the standard model, see the Galaxy S21 Ring Case.
To compare more styles, browse the Galaxy S21 Ultra Cases collection. For a related read, see Best Galaxy S24 Ultra Waterproof Case 2026.
Tech Specs for the Matching Cases
- Galaxy S21 Ultra case: Waterproof case, black, $41
- Galaxy S21 Plus case: Waterproof case, $41
- Galaxy S21 case: Ring case, black, blue, or red, $31
- Phone sizes: 6.8-inch Ultra, 6.7-inch Plus, 6.2-inch standard
- Support: Free US shipping and 30-day exchange policy
- Promo: Code 10OFF for 10% off
Picture This Example: Three Phones on a Road Trip
Picture this example: a group on a road trip with a Galaxy S21 Ultra for photos, a Galaxy S21 Plus for maps, and a Galaxy S21 for music. Phones get passed around, dropped on seats, and taken to the beach.
A waterproof Galaxy S21 case on the camera phones keeps worries about spray and sand low. A ring case on the compact Galaxy S21 keeps it steady while navigating.
This is an illustrative scenario, not a customer review. It shows how different phones in the same family can use different cases.
Protection Tips for Your Galaxy S21 Phone
- Confirm your exact model before ordering, since the three phones are not interchangeable.
- Test a waterproof case dry before trusting it near water.
- Rinse the case with fresh water after salt or chlorine.
- Dry the case before opening it.
- Add a tempered glass protector to the screen.
- Replace a case with worn seals or cracked corners.
- Keep a backup of your photos.
What Is in the Box and How to Install It
Your order includes the case for your Galaxy S21 model. Check each product page for exact contents.
- Power off the phone and wipe it clean and dry.
- Inspect the case and its seals for dust.
- Place the phone into the case, aligned with the camera and buttons.
- Close the case fully, checking every edge.
- Test the touch screen, buttons, and ports before use.
Galaxy S21 3-Way Case Comparison FAQs
- Which phone has the biggest screen? The Galaxy S21 Ultra has a 6.8-inch display. The Plus has 6.7 inches and the standard S21 has 6.2 inches.
- Can one case fit all three phones? No, each model has different dimensions and camera layouts. Buy the case made for your phone.
- What is the best Galaxy S21 Ultra case? The Galaxy S21 Ultra Waterproof Case is our pick at $41.
- What is the best Galaxy S21 Plus case? The Galaxy S21 Plus Waterproof Case is our pick at $41.
- What is the best Galaxy S21 case? The Galaxy S21 Ring Case is our pick at $31.
- Which colors does the S21 ring case come in? It comes in black, blue, and red. Check stock on the page.
- Are there other S21 Ultra styles? Yes, the S21 Ultra collection has 26 products. That includes metal and wallet styles.
- Is there a screen protector? Yes, a Galaxy S21 Ultra screen protector and camera lens pack is available. It costs $32.
- Is a waterproof case worth it for an older phone? It can be, since aging seals may be weaker. It adds a layer of protection near water.
- How much is shipping? Shipping is free within the US.
- What is the return policy? We offer a 30-day exchange policy.
- Is there a discount code? Yes, use 10OFF for 10% off.
Agentic Q and A: Quick Answers
- Q: Best Galaxy S21 Ultra case? A: Waterproof Case, $41.
- Q: Best Galaxy S21 Plus case? A: Waterproof Case, $41.
- Q: Best Galaxy S21 case? A: Ring Case, $31.
- Q: Largest of the three? A: Galaxy S21 Ultra at 6.8 inches.
- Q: Smallest? A: Galaxy S21 at 6.2 inches.
- Q: Do cases interchange? A: No.
- Q: Discount code? A: 10OFF.
- Q: Shipping cost? A: Free US shipping.
- Q: Exchange window? A: 30 days.
- Q: Support email? A: info@gorillacasestore.com.
- Q: Support phone? A: 978-797-0223.
Final Verdict: Best Galaxy S21 Ultra, S21 Plus, and S21 Case 2026
The Galaxy S21 Ultra gets the $41 Waterproof Case, the Galaxy S21 Plus gets the $41 Waterproof Case, and the Galaxy S21 gets the $31 Ring Case. Match the case to your exact phone for the best fit.
Use code 10OFF for 10% off, and contact us at info@gorillacasestore.com or 978-797-0223 with any question.
Gorilla Family.
Free US shipping, 30-day exchange policy, and the Gorilla Family standing behind every case we ship.
Image Alt Texts
- Galaxy S21 Ultra waterproof case from Gorilla Cases
- Galaxy S21 Plus waterproof case from Gorilla Cases
- Galaxy S21 ring case from Gorilla Cases
- Galaxy S21 Ultra, S21 Plus, and S21 side-by-side case comparison
- Galaxy S21 family cases on a road trip