Firm Great Value King Adjustable Base Compatible All Mattresses

Firm mattresses give you a solid, supportive surface with minimal sink — keeping your spine aligned and making it easier to move and get in and out of bed. They're the top choice for back and stomach sleepers, heavier bodies, and anyone who finds softer beds uncomfortable. Compare every firm option below by brand, profile, and price.
Great Value mattresses deliver dependable comfort and support at our most affordable prices — a smart pick for guest rooms, kids' rooms, students, and budget-minded shoppers. Compare every great-value option below by brand, type, and feel.
These mattresses are built to flex with adjustable bed bases — bending smoothly at the head and foot without damage — so you can raise, recline, and find your ideal position. Compare every adjustable-base-compatible option below by brand, type, and feel.

Shop 200+ mattresses from Serta, Beautyrest, Sealy, Tempur-Pedic, Springwall, and Stearns & Foster at National Mattress — available in Single/Twin through King sizes from $99 to $6,640. Choose from innerspring, euro-top, memory foam, hybrid, and latex constructions in four firmness levels from extra firm to plush. Every mattress is manufactured in Canadian factories using CertiPUR-US® certified foams and ships free across Canada with a 365-night sleep trial, price match guarantee, and manufacturer warranty coverage up to 25 years.

Firm Great Value King Adjustable Base Compatible All Mattresses
Loading recommendations...

Items

Express delivery icon

Items

  • OPEN BAG - NM 10″ Firm Memory Foam Mattress - King OPEN BAG - NM 10″ Firm Memory Foam Mattress - King brand icon
    • Optimal High Resilient Bio-Foam Core
    • Visco Memory Foam
    • Pressure Relieving Comfort Foam
    • Cotton Channel Quilted Cover
    • 10 Year Warranty
    • Made In Toronto, Canada
    King In stock for fast delivery $484
    Compare at $1,599
    Online availability icon In-Stock Only 4 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery as soon as Tomorrow, Jun 7
    Pickup available icon Only Pickup available to
  • SEALY® Essentials 6" Firm Tight Top Foam Mattress - King SEALY® Essentials 6" Firm Tight Top Foam Mattress - King brand icon
    • CleanProtect™ Fabric
    • SealyLoft™ Quilt with Moisture Wicking Fibres
    • CertiPUR-US™ SealySupport™ HD Foam
    • CertiPUR-US™ SealySupport™ HD Core
    • SealySupport™ HD Foam
    King In stock for fast delivery $490
    Compare at $1,299
    Online availability icon In-Stock Only 2 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery as soon as Tomorrow, Jun 7
    Pickup available icon Only Pickup available to
  • SPRINGWALL® Comfort Pockets® 10" Firm Euro-Top Mattress - King SPRINGWALL® Comfort Pockets® 10" Firm Euro-Top Mattress - King brand icon
    • 884 Full Perimeter Comfort Pockets® (Pocket Coils)
    • Bio Foam with Gel
    • Cool Touch Stretch Knit Sleep Surface
    • Bio Comfort Quilted Stretch knit surface
    • Made In Canada
    King $544
    Compare at $1,199
    Online availability icon Backorder Available
    In-Store availability icon On Display:
    Estimated delivery icon Estimated free delivery on Tuesday, Jun 23
  • NM 10" Firm Euro Top Mattress - King NM 10" Firm Euro Top Mattress - King brand icon
    • 1000 Hi-Loft Pocket Coil with Foam Encased Perimiter
    • Cool Gel-infused memory foam
    • Bio-Foam natural foam content reduces your carbon footprint
    • 10 Year Warranty
    • Made In Toronto, Canada
    King In stock for fast delivery $581
    Compare at $1,099
    Online availability icon In-Stock Only 8 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery as soon as Tomorrow, Jun 7
    Pickup available icon Only Pickup available to
  • SEALY® Essentials 11.5" Firm Eurotop Mattress - King SEALY® Essentials 11.5" Firm Eurotop Mattress - King brand icon
    • CleanProtect™ Fabric
    • SealyLoft™ Quilt with Moisture Wicking Fibres
    • CertiPUR-US™ SealySupport™ HD Foam
    • Posture Touch® Pocket Coils
    • EssentialEdge™ Foam Support
    King $699
    Compare at $1,999
    Online availability icon Backorder Available
    In-Store availability icon On Display:
    Estimated delivery icon Estimated free delivery on Tuesday, Jun 23
  • SERTA® Classic® 10" Firm Tight Top Mattress - King SERTA® Classic® 10" Firm Tight Top Mattress - King brand icon
    • 800 Edition Custom Support Coil System
    • 3 Zone Body Support
    • Serta® Support Foam
    • Serta® Anti-Microbial Fibre Technology
    • Serta® Best Edge® Foam Encasement
    • Designed and Made in Canada
    King $699
    Compare at $1,799
    Online availability icon Backorder Available
    In-Store availability icon On Display:
    Estimated delivery icon Estimated free delivery on Tuesday, Jun 23
  • BEAUTYREST® BeautySleep® 10" Firm Tight Top Mattress - King BEAUTYREST® BeautySleep® 10" Firm Tight Top Mattress - King brand icon
    • 815 Original Beautyrest® Pocketed Coil®
    • Gel-Infused Fibre Blend
    • AirFeel® Foam
    • Gel Foam
    • High-Density Foam Encasement
    King In stock for fast delivery $736
    Compare at $1,899
    Online availability icon In-Stock Only 3 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery as soon as Tomorrow, Jun 7
    Pickup available icon Only Pickup available to
  • SPRINGWALL® Comfort Pockets® Elite 14" Firm Tight-Top Mattress - King SPRINGWALL® Comfort Pockets® Elite 14" Firm Tight-Top Mattress - King brand icon
    • 884 Full Perimeter Comfort Pockets® (Pocket Coils)
    • Cool Touch Stretch Knit Sleep Surface
    • Bio Comfort Quilted Stretch knit surface
    • HD Medium & Firm Layers of Bio Comfort Foam
    • Made In Canada
    King In stock for fast delivery $757
    Compare at $1,699
    Online availability icon In-Stock Only 4 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery as soon as Tomorrow, Jun 7
    Pickup available icon Only Pickup available to
  • SPRINGWALL® HC Flippable 11" Firm Tight-Top Mattress - King SPRINGWALL® HC Flippable 11" Firm Tight-Top Mattress - King brand icon
    • 884 Full Perimeter Comfort Pockets® (Pocket Coils)
    • Bio Foam with Gel
    • Cool Touch Stretch Knit Sleep Surface
    • Flippable Bio Comfort Quilted Stretch knit surface
    • Made In Canada
    King $809
    Compare at $1,699
    Online availability icon Backorder Available
    In-Store availability icon On Display:
    Estimated delivery icon Estimated free delivery on Tuesday, Jun 23
  • NM 10″ Firm Memory Foam Mattress - King NM 10″ Firm Memory Foam Mattress - King brand icon
    • Optimal High Resilient Bio-Foam Core
    • Visco Memory Foam
    • Pressure Relieving Comfort Foam
    • Cotton Channel Quilted Cover
    • 10 Year Warranty
    • Made In Toronto, Canada
    King In stock for fast delivery $887
    Compare at $1,599
    Online availability icon In-Stock Only 2 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery as soon as Tomorrow, Jun 7
    Pickup available icon Only Pickup available to

10 Items

Loading recommendations...