Side Sleeper King Mattresses

Shop Side Sleeper King Mattresses at Mattress Firm to explore king-size options for shoppers who prefer sleeping on their side. Browse a variety of mattress choices and find the right fit for your bedroom, sleep style and budget.

Beautyrest Black Series Four 17.25" Plush Summit Pillow Top Mattress

314

Starting at

$5899⁰⁰

$6599⁰⁰

$700 OFF

Plush Comfort, best for

Side Sleepers
Pain
Temperature
Bed Partner
Toss and Turn

$300 ⁶ adjustable base instant gift with purchase.

Tempur-Pedic TEMPUR-LuxeBreeze Soft 13" Mattress

1623

Starting at

$6299⁰⁰

$6599⁰⁰

$300 OFF

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Temperature
Allergies
Toss and Turn

$300 Instant Gift⁴ with purchase of a mattress set + Calm app 3-month free trial.

Serta Perfect Sleeper Nurture Night 14.5" Pillow Top Mattress

1185

Starting at

$1249⁰⁰

Plush Comfort, best for

Side Sleepers
Pain
Temperature
Bed Partner
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Serta Perfect Sleeper Midsummer Nights 11" Plush Eurotop Mattress

929

Starting at

$999⁰⁰

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Beautyrest Black Series Two 15.25" Plush Mattress

237

Starting at

$3499⁰⁰

$3899⁰⁰

$400 OFF

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

$300 ⁶ adjustable base instant gift with purchase.

Tempur-Pedic TEMPUR-LuxeAdapt 13" Soft Previous Generation Mattress

2106

Starting at

$3429⁷⁷

$4899⁰⁰

$1469 OFF

Plush Comfort, best for

Side Sleepers
Bed Partner
Pain
Temperature
Toss and Turn

Sealy Essentials Winter Green 13" Plush Euro Pillow Top Mattress

549

Starting at

$1459⁹⁹

Plush Comfort, best for

Side Sleepers
Bed Partner
Pain
Temperature
Toss and Turn
Allergies

Tempur-Pedic TEMPUR-LuxeAdapt 2.0 13" Soft Mattress

1580

Starting at

$5299⁰⁰

$5599⁰⁰

$300 OFF

Plush Comfort, best for

Side Sleepers
Pain
Allergies
Bed Partner
Toss and Turn
Temperature

$300 Instant Gift⁴ with purchase of a mattress set + Calm app 3-month free trial.

Kingsdown Crown Imperial 16" Plush Euro Top Mattress

185

Starting at

$6899⁰⁰

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Stearns & Foster Reserve 17" Plush Euro Pillow Top Mattress

473

Starting at

$5399⁰⁰

$6199⁰⁰

$800 OFF

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

$300 Instant Gift⁴ with purchase of a mattress set.

Serta Classic Blissville 12.5" Plush Euro Top Mattress

281

Starting at

$1799⁹⁹

Plush Comfort, best for

Side Sleepers
Pain
Temperature
Bed Partner
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Beautyrest Black Series One 14.5" Plush Pillow Top Mattress

287

Starting at

$3099⁰⁰

$3499⁰⁰

$400 OFF

Plush Comfort, best for

Side Sleepers
Pain
Temperature
Allergies
Bed Partner
Toss and Turn

$300 ⁶ adjustable base instant gift with purchase.

Kingsdown Crown Imperial 15" Plush Mattress

Starting at

$5999⁰⁰

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Stearns & Foster Estate 15" Plush Euro Pillow Top Mattress

991

Starting at

$3099⁰⁰

$3299⁰⁰

$200 OFF

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Temperature
Allergies
Toss and Turn

$300 Instant Gift⁴ with purchase of a mattress set.

Tempur-Pedic TEMPUR-ProAdapt 2.0 12" Soft Mattress

3564

Starting at

$3999⁰⁰

$4199⁰⁰

$200 OFF

Plush Comfort, best for

Side Sleepers
Pain
Allergies
Bed Partner
Toss and Turn
Temperature

$300 Instant Gift⁴ with purchase of a mattress set + Calm app 3-month free trial.

Serta Perfect Sleeper Nurture Night 13.5" Plush Mattress

968

Starting at

$1099⁰⁰

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Purple RestorePlus 13" Soft Hybrid Mattress

3568

Starting at

$3999⁰⁰

$4399⁰⁰

$400 OFF

Plush Comfort, best for

Side Sleepers
Pain
Allergies
Bed Partner
Toss and Turn
Temperature

Beautyrest BR800 Greenwood 13.5" Plush Pillow Top Mattress

2825

Starting at

$819⁹⁹

$1499⁹⁹

$680 OFF

Plush Comfort, best for

Side Sleepers
Bed Partner
Toss and Turn
Temperature
Pain

FREE ADJUSTABLE BASE ³ with code ELEVATE

Purple Rejuvenate Royale Crown Mattress

Starting at

$10399⁰⁰

$10899⁰⁰

$500 OFF

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

$300 adjustable base instant gift with purchase.

Dreamcloud PressureSmart Technology Plush Mattress

843

Starting at

$2149⁰⁰

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Temperature
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Sealy Essentials Autumn Ash 10.5" Plush Mattress

Starting at

$1049⁹⁹

Plush Comfort, best for

Side Sleepers
Pain
Temperature
Bed Partner
Toss and Turn
Allergies

Beautyrest BR800 13.5" Plush Pillow Top Mattress

2809

Starting at

$1499⁹⁹

Plush Comfort, best for

Side Sleepers
Toss and Turn
Pain
Bed Partner
Temperature

FREE ADJUSTABLE BASE ³ with code ELEVATE

Sleepy's By Sealy Memory Foam Plush Mattress

2845

Starting at

$999⁹⁹

Plush Comfort, best for

Side Sleepers
Pain
Bed Partner
Toss and Turn
Temperature

FREE ADJUSTABLE BASE ³ with code ELEVATE

Beautyrest Silver BRS900 12" Plush Mattress

1166

Starting at

$1699⁹⁹

Plush Comfort, best for

Side Sleepers
Temperature
Pain
Bed Partner
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Beautyrest BR800 12" Plush Euro Top Mattress

762

Starting at

$1399⁹⁹

Plush Comfort, best for

Side Sleepers
Toss and Turn
Pain
Bed Partner
Temperature

Sealy Tanglewood 2.1 Soft Pillow Top Mattress

Starting at

$1499⁹⁹

Plush Comfort, best for

Side Sleepers
Temperature
Pain
Bed Partner
Toss and Turn

FREE ADJUSTABLE BASE ³ with code ELEVATE

Side sleeper king mattresses are designed for people who spend most of the night on one side and want generous space to stretch out without giving up cushioning or support. A king mattress measures about 76 inches wide by 80 inches long, making it a practical choice for couples, taller sleepers and anyone who prefers room to change positions. Side sleeping places more concentrated pressure on the shoulder, hip and outer knee, so the surface should have enough flexibility to contour around those areas while still supporting the body from head to toe. In many cases, a medium to medium-soft feel offers a useful balance: the comfort layers can cushion prominent joints, while the support core helps keep the midsection from sinking too deeply. The right feel depends on body type, personal preference and whether the mattress is shared. A lighter sleeper may prefer a softer surface that allows the shoulders and hips to settle in, while a larger sleeper may need stronger support beneath the cushioning to maintain a level sleep posture. When comparing side sleeper king mattresses, look for pressure-relieving foam or other responsive comfort materials, a supportive transition layer and a durable base that resists sagging over time. The best match should feel welcoming when you first lie down and remain supportive after several hours, when small gaps between the body and mattress can turn into morning stiffness.

Mattress construction can make a noticeable difference in how a king mattress feels for side sleeping. All-foam designs often provide a close, quiet feel that can ease pressure around the shoulders and hips, with memory foam conforming gradually as body heat and weight settle into the surface. Responsive foam can make it easier to move from one side to the other without feeling stuck. Hybrid mattresses combine foam or other cushioning materials with individually encased coils, creating a blend of contouring, airflow and support. Zoned coils or zoned transition materials may provide firmer reinforcement beneath the center of the body while allowing more give near the shoulders, helping promote a more even alignment. A mattress with a thick comfort layer can be helpful for side sleepers who wake with tenderness along the hip or shoulder, although too much softness may allow the spine to curve. Cooling features are also worth considering, particularly for couples sharing a king surface. Breathable covers, ventilated foams and coil systems that allow air to move through the mattress can help reduce heat buildup. Bedding, bedroom temperature and sleepwear affect comfort as well, so a cooler-feeling mattress is one part of a broader sleep setup. Motion isolation may matter when two people share the bed, since foam and individually encased coils can reduce the transfer of movement when a partner turns over. Edge support can preserve usable space across the full surface and make it easier to sit down or stand up. Comparing firmness, materials, height, trial terms and foundation requirements can help narrow the selection without relying on feel alone.

A side sleeper king mattress can be a thoughtful choice for a couple creating a more spacious bedroom, a household replacing an older sleep surface or a gift for someone settling into a new home. It may also suit sleepers whose shoulders and hips feel sore after nights on a surface that is too firm, though persistent discomfort can have many causes and may warrant professional advice. Before choosing, consider the sleeper’s usual position, body weight, sensitivity to heat, preference for a close or buoyant feel and whether the mattress will be used alone or by two people. Measuring the bedroom and checking the path to the room is especially important with a king size, since doorways, stairways and bed frames need to accommodate its larger dimensions. A compatible foundation or adjustable base may also affect the feel and warranty requirements. Give the mattress enough time for its materials to settle and for the body to adjust, especially when moving from a significantly different firmness. Pillows matter, too: side sleepers often benefit from enough loft to fill the space between the head and shoulder, keeping the neck closer to neutral. Some sleepers prefer a pillow between the knees or beneath the top arm for added comfort and alignment. If sleeping habits vary between partners, comparing king options with balanced cushioning and reliable support can make the shared surface more accommodating. For shoppers who primarily sleep on their stomach, explore King Stomach Sleeper Mattresses for constructions that may better support that position. With thoughtful attention to pressure relief, support, temperature and size, a king mattress can create a roomy, restorative place to settle in during cooler months and throughout the year.

What should side sleepers look for in a king mattress? + -

Side sleepers may prefer a mattress with cushioning comfort and responsive support. Look for materials that contour around the shoulders and hips while helping maintain a neutral spinal position.

What mattress firmness is best for side sleepers? + -

Many side sleepers enjoy a medium-soft to medium-firm feel because it can provide pressure-relieving comfort without feeling too plush. Personal preference, body type and sleeping position can all influence the ideal firmness.

Which mattress materials are comfortable for side sleepers? + -

Memory foam, latex and hybrid mattresses can all be comfortable options for side sleepers. Memory foam offers contouring comfort, latex provides responsive cushioning and hybrids combine comfort layers with supportive coils.

How can a mattress support proper alignment for side sleeping? + -

A supportive side sleeper mattress should cushion the shoulders and hips while keeping the middle of the body from sinking too deeply. A comfort layer with responsive support can help promote a more naturally aligned sleep position.

Can couples with different sleep preferences share a side sleeper mattress? + -

Yes. Couples may want to consider a mattress with balanced support, motion-reducing comfort layers or customizable firmness options. These features can help accommodate different preferences while maintaining comfortable support for side sleeping.