Core Support King Mattresses

Explore Core Support King Mattresses at Mattress Firm to find a king-size mattress that fits your sleep preferences, bedroom space and budget. Browse a range of options and shop with guidance from Sleep Experts® to make choosing your next mattress easy.

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Sleepy's By Sealy Memory Foam Medium Mattress

3489

Starting at

$889⁹⁹

Medium Comfort, best for

Back, Side, Stomach Sleepers
Pain
Bed Partner
Toss and Turn
Temperature

FREE ADJUSTABLE BASE ³ with code ELEVATE

Beautyrest PressureSmart 2.0 Firm 11" Mattress

Starting at

$1099⁹⁹

$2199⁹⁹

$1100 OFF

Firm Comfort, best for

Back, Stomach Sleepers
Temperature
Bed Partner
Pain
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Serta Perfect Sleeper Charlotte 2.0 Medium Euro Top Mattress

2616

Starting at

$1499⁹⁹

Medium Comfort, best for

Back, Side, Stomach Sleepers
Pain
Toss and Turn
Temperature
Bed Partner

FREE ADJUSTABLE BASE ³ with code ELEVATE

Serta Perfect Sleeper Sleep Excellence Medium PillowTop Mattress

1438

Starting at

$1999⁹⁹

Medium Comfort, best for

Back, Side, Stomach Sleepers
Pain
Toss and Turn
Temperature
Bed Partner

FREE ADJUSTABLE BASE ³ with code ELEVATE

Tempur-Pedic TEMPUR-Adapt 11" Medium Previous Generation Mattress

3639

Starting at

$2029⁷⁷

$2899⁰⁰

$869 OFF

Medium Comfort, best for

Back, Side, Stomach Sleepers
Pain
Temperature
Allergies
Bed Partner
Toss and Turn

Beautyrest BR800 13.5" Plush Pillow Top Mattress

2788

Starting at

$1499⁹⁹

Plush Comfort, best for

Side Sleepers
Toss and Turn
Pain
Bed Partner
Temperature

FREE ADJUSTABLE BASE ³ with code ELEVATE

Beautyrest Silver BRS900 11.75" Extra Firm Mattress

3298

Starting at

$1699⁹⁹

Extra Firm Comfort, best for

Back, Stomach Sleepers
Temperature
Pain
Allergies
Bed Partner
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Beautyrest BR800 11.25" Firm Mattress

2235

Starting at

$1299⁹⁹

Firm Comfort, best for

Back, Stomach Sleepers
Toss and Turn
Pain
Bed Partner
Temperature

FREE ADJUSTABLE BASE ³ with code ELEVATE

Stearns & Foster Estate 14.5" Firm Mattress

1816

Starting at

$2799⁰⁰

$3099⁰⁰

$300 OFF

Firm Comfort, best for

Back, Stomach Sleepers
Pain
Bed Partner
Temperature
Allergies
Toss and Turn

Receive $300 Instant Gift⁴ with purchase.

Sealy Essentials Sudley 8.5" Firm Mattress

989

Starting at

$499⁹⁹

$999⁹⁹

$500 OFF

Firm Comfort, best for

Back, Stomach Sleepers
Pain
Temperature
Bed Partner
Toss and Turn

Beautyrest BR800 13.5" Medium Pillow Top Mattress

1865

Starting at

$1499⁹⁹

Medium Comfort, best for

Back, Side, Stomach Sleepers
Toss and Turn
Pain
Bed Partner
Temperature

FREE ADJUSTABLE BASE ³ with code ELEVATE

Beautyrest Silver BRS900-C 13.75" Extra Firm Mattress

1813

Starting at

$1999⁹⁹

Extra Firm Comfort, best for

Back, Stomach Sleepers
Temperature
Pain
Bed Partner
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Beautyrest Silver BRS900 11.75" Medium Firm Mattress

1746

Starting at

$1099⁹⁹

Medium Comfort, best for

Back, Side, Stomach Sleepers
Allergies
Bed Partner
Temperature
Pain
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Purple Original Mattress

59751

Starting at

$1760⁰⁰

$2199⁰⁰

$439 OFF

Medium Comfort, best for

Back, Side, Stomach Sleepers
Temperature
Pain
Bed Partner
Toss and Turn
Allergies

Sleepy's By Sealy Slumber Cushion Firm Mattress

303

Starting at

$1999⁹⁹

Medium Comfort, best for

Back, Side, Stomach Sleepers
Bed Partner
Toss and Turn
Pain
Temperature

FREE ADJUSTABLE BASE ³ with code ELEVATE

Beautyrest BR800 12" Plush Euro Top Mattress

737

Starting at

$1399⁹⁹

Plush Comfort, best for

Side Sleepers
Toss and Turn
Pain
Bed Partner
Temperature

FREE ADJUSTABLE BASE ³ with code ELEVATE

Sleepy's By Sealy Slumber Medium Mattress

176

Starting at

$709⁹⁹

$2299⁹⁹

$1590 OFF

Medium Comfort, best for

Back, Side, Stomach Sleepers
Bed Partner
Toss and Turn
Pain
Temperature

FREE ADJUSTABLE BASE ³ with code ELEVATE

Serta Perfect Sleeper Nurture Night 12" Firm Mattress

1188

Starting at

$999⁰⁰

Firm Comfort, best for

Back, Stomach Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Beautyrest Silver BRS900 12" Plush Mattress

1144

Starting at

$1699⁹⁹

Plush Comfort, best for

Side Sleepers
Temperature
Pain
Bed Partner
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Serta Perfect Sleeper Nurture Night 14.5" Pillow Top Mattress

1130

Starting at

$1249⁰⁰

Plush Comfort, best for

Side Sleepers
Pain
Temperature
Bed Partner
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Nectar Premier 13" Medium Memory Foam Mattress

487

Starting at

$1099⁰⁰

$1799⁰⁰

$700 OFF

Medium Comfort, best for

Back, Side, Stomach Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

Nectar Classic 12" Firm Memory Foam Mattress

232

Starting at

$899⁰⁰

$1399⁰⁰

$500 OFF

Firm Comfort, best for

Back, Stomach Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

Serta Perfect Sleeper Nurture Night 13.5" Medium Mattress

1020

Starting at

$1099⁰⁰

Medium Comfort, best for

Back, Side, Stomach Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Serta Perfect Sleeper Oasis Sleep 14.5" Pillow Top Mattress

1009

Starting at

$1399⁰⁰

Medium Comfort, best for

Back, Side, Stomach Sleepers
Pain
Temperature
Bed Partner
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Serta Perfect Sleeper Oasis Sleep 12" Extra Firm Mattress

905

Starting at

$1399⁰⁰

Extra Firm Comfort, best for

Back, Stomach Sleepers
Pain
Temperature
Bed Partner
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Serta Perfect Sleeper Nurture Night 13.5" Plush Mattress

917

Starting at

$1099⁰⁰

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

A core support king mattress is designed to promote balanced support from the center of the mattress outward, helping maintain a more stable sleep surface for couples, combination sleepers and anyone who prefers a supportive feel. With a spacious 76-by-80-inch sleep surface, a king mattress gives each person more room to stretch out while core-focused construction helps support the midsection, hips and lower back. Depending on the model, core support may come from individually wrapped innerspring coils, reinforced coil zones, high-density foam layers or a combination of materials. Choosing the right design can help you find the comfort, pressure relief and support you need for more restful zzz's Explore core support king mattresses in a range of feels, including plush, medium and firm options, to match your preferred sleep position and comfort level. Side sleepers may appreciate pressure-relieving foam and cushioning around the shoulders and hips, while back and stomach sleepers often prefer a firmer, more supportive king mattress that helps keep the body comfortably aligned. Couples can also look for motion-isolating materials, reinforced edges and breathable construction to create a more comfortable shared sleep space. Compare king size mattresses by comfort, materials, support system and sleep benefits to find the mattress that helps you sleep well so you can live well

What are core support king mattresses? + -

Core support king mattresses are designed with a supportive center made from materials such as innersprings, foam or a combination of both. This construction contributes to the mattress’s overall feel and structure.

What materials are used in core support mattresses? + -

Common materials include individually wrapped coils, traditional innersprings, memory foam, polyfoam and latex. Some mattresses combine multiple materials in layers to create a specific comfort and support profile.

How do I choose the right comfort feel? + -

Consider whether you prefer a plush, medium or firm feel, along with the amount of cushioning and contouring you enjoy. Comparing mattress materials and trying different comfort levels can help you find a feel that suits your preferences.

Can core support mattresses have foam comfort layers? + -

Yes. Many core support mattresses pair a coil or foam core with comfort layers made from memory foam, polyfoam or latex. These layers can influence the mattress’s cushioning, pressure response and overall feel.

What type of foundation works with a core support mattress? + -

Core support mattresses may be compatible with foundations, platform beds, adjustable bases or other supportive bed frames, depending on the manufacturer’s guidelines. Review the product specifications to confirm the recommended foundation.