The Sealy Response Performance 14-Inch Cushion Firm Euro Pillow Top Mattress is our top choice for a firm king mattress. This premium mattress combines the support and durability of an innerspring mattress with the comfort of a pillow top. The 14-inch height provides ample support for all body types, making it a suitable option for couples with different sleeping preferences. The Sealy Response Performance mattress features Sealy's exclusive Posturepedic technology, which is designed to provide targeted support to the heaviest parts of your body. This helps to alleviate pressure points and promote proper spinal alignment for a restful night's sleep. The cushion firm feel of this mattress strikes the perfect balance between comfort and support, making it a great choice for those who prefer a medium-firm feel.1. Sealy Response Performance 14-Inch Cushion Firm Euro Pillow Top Mattress
If you're looking for a firm king mattress that will keep you cool and comfortable throughout the night, the Serta Perfect Sleeper Select Kleinmon II is a great option. This mattress features Serta's Cool Twist gel foam and EverCool® Fuze gel memory foam layers, which work together to provide superior temperature regulation and pressure relief. The Kleinmon II also boasts a 886 Custom Support® Firm Coil System, which provides exceptional support and helps to reduce motion transfer. This makes it an ideal choice for couples who may be disturbed by their partner's movements during the night. The firm feel of this mattress is perfect for back and stomach sleepers, as it helps to keep the spine properly aligned and supported.2. Serta Perfect Sleeper Select Kleinmon II Firm King Mattress
For those who prefer an extra firm feel, the Beautyrest Silver BRS900 12-Inch Extra Firm Innerspring Mattress is a top choice. This mattress is made with Beautyrest's DualCool™ Technology, which helps to keep your mattress fresh and cool while you sleep. It also features gel memory foam and 800 Series Beautyrest® Pocketed Coil® Technology for exceptional support and comfort. The BRS900 mattress also has a firm comfort rating of 10 out of 10, making it the firmest option on our list. This makes it an excellent choice for those who suffer from back pain or prefer a more supportive mattress. With the added benefit of Beautyrest's pressure-relieving technology, you can wake up feeling refreshed and pain-free.3. Beautyrest Silver BRS900 12-Inch Extra Firm Innerspring Mattress
The Tempur-Pedic TEMPUR-ProAdapt 12-Inch Firm Mattress is a luxurious choice for those who want the ultimate in comfort and support. This mattress features TEMPUR-ES® Comfort Layer and TEMPUR-APR™ Support Layer, which provide personalized support and pressure relief. Additionally, it has a SmartClimate® Dual Cover System that helps to keep you cool and comfortable throughout the night. The TEMPUR-ProAdapt is also designed with TEMPUR® material, which is known for its ability to conform to your body and relieve pressure points. This makes it an excellent choice for those who suffer from chronic pain or discomfort while sleeping. With a firm feel and luxurious features, this mattress is truly a top-of-the-line option.4. Tempur-Pedic TEMPUR-ProAdapt 12-Inch Firm Mattress
The Stearns & Foster Estate Rockwell Luxury Firm King Mattress is a high-end option that offers both support and luxury. This mattress features Stearns & Foster's exclusive IntelliCoil® Advanced Coil System, which adapts to your body and provides targeted support. It also has PrimaCool™ Elite Gel Memory Foam and PrimaSense™ Gel Foam layers for added comfort and pressure relief. The Estate Rockwell has a firm comfort rating of 8.5 out of 10, making it a great choice for those who prefer a firmer feel. The hand-tufted design and SilkAir™ Fiber cover add a touch of luxury to this already impressive mattress. With its combination of support and plush comfort, the Stearns & Foster Estate Rockwell is a top contender for the best firm king mattress.5. Stearns & Foster Estate Rockwell Luxury Firm King Mattress
The Simmons Beautyrest Black Hybrid X-Class Firm King Mattress is a hybrid mattress that combines the support of an innerspring mattress with the comfort of memory foam. This mattress features Beautyrest's exclusive T3 Pocketed Coil® Technology, which provides targeted support and reduces motion transfer. The X-Class Firm also has BlackICE™ 4.0 Technology, which helps to keep you cool and comfortable throughout the night. The RightTemp™ Memory Foam and gel memory foam layers work together to provide pressure relief and contour to your body's natural curves. With a firm feel and advanced features, this mattress is a top choice for those seeking a hybrid option.6. Simmons Beautyrest Black Hybrid X-Class Firm King Mattress
The Sleep Number 360 c2 Smart Bed King Mattress is a unique option that allows you to customize your firmness level to your exact preference. This mattress features adjustable air chambers that can be controlled using a remote or the Sleep Number app. This allows you to find your perfect level of firmness for a comfortable and restful night's sleep. The 360 c2 also has a responsive air technology that automatically adjusts to your body's movements and changes in position. This helps to keep you supported and comfortable throughout the night. With its customizable firmness and innovative technology, the Sleep Number 360 c2 is a top choice for those seeking a personalized sleep experience.7. Sleep Number 360 c2 Smart Bed King Mattress
The Purple Hybrid Premier 3 13-Inch Firm King Mattress is a unique option that features a combination of purple grid and responsive support coils. This provides the perfect balance of support and pressure relief, making it a great choice for all types of sleepers. The purple grid is designed to adapt to your body and provide targeted support, while the coils add a layer of responsiveness and durability. The Hybrid Premier 3 also has Hyper-Elastic Polymer™ material, which is known for its cooling properties and ability to relieve pressure points. This makes it an ideal choice for those who tend to sleep hot or suffer from chronic pain. With its unique combination of materials and firm feel, the Purple Hybrid Premier 3 is a top contender for the best firm king mattress.8. Purple Hybrid Premier 3 13-Inch Firm King Mattress
The Casper Wave Hybrid 13-Inch Firm King Mattress is a hybrid option that provides exceptional support and comfort. This mattress features Casper's exclusive Zoned Support™ Pro technology, which provides targeted support and pressure relief to different areas of the body. It also has gel pods and breathable foams for added comfort and temperature regulation. The Wave Hybrid also has coils that are designed to reduce motion transfer and provide durable support. This makes it an ideal choice for couples who may have different sleeping preferences. With its firm feel and advanced features, the Casper Wave Hybrid is a top choice for those seeking a supportive and comfortable mattress.9. Casper Wave Hybrid 13-Inch Firm King Mattress
The Saatva Classic 11.5-Inch Firm Innerspring Mattress is a high-quality option that provides exceptional support and comfort. This mattress features coil-on-coil construction, which provides targeted support and reduces motion transfer. It also has comfort layers made from organic cotton and memory foam, which provide pressure relief and a plush feel. The Saatva Classic also has a firm comfort rating of 8 out of 10, making it a great choice for those who prefer a firmer feel. The spinal zone technology and dual perimeter edge support make this mattress ideal for those who suffer from back pain or want extra support while getting in and out of bed. With its high-quality materials and firm feel, the Saatva Classic is a top choice for a firm king mattress.10. Saatva Classic 11.5-Inch Firm Innerspring Mattress