Best King Size Mattress Deals Online in the UK (25 Deals Found)

Last Updated - 04/04/2026 Sort By:

Best Choice
dosleeps

New
dosleeps King Size Mattress 5FT,9 Inch 9-Zone Orthopedic Mattress with Memory Foam & Pocket Springs and 3D Breathable Fa
Comfortable Mattress: Crafted with comfort memory foam and 9-zone individually pocket spring, our king size mattress del

£115.59 £135.99
dosleeps

New
dosleeps King Size Mattress 5FT | 11" Extra Thick Memory Foam & Pocket Sprung | 9-Zone Orthopedic Support,Medium Firm,Mo
★【A GOOD NIGHT SLEEP】With an innovative 9 Zone Support System constructed by individual spring coil pockets. each spring

£181.99
New
LUXURY ORTHOPAEDIC 4000 POCKET SPRUNG MATTRESS 3FT 4FT 4FT6 DOUBLE 5FT KING SIZE
Available In UK Sizes: 2FT6 - 3FT - 4FT - 4FT6 - 5FT - 6FT. It is a safe and natural mattress that is supportive, comfor

£151.16
Best Value
Twirest

New
Twirest King Mattress, Hybrid Memory Foam and Spring, Zonal Support, Decompression, Medium Firm, Soft and Breathable Clo
Innovative Design: Twirest hybrid spring mattress adopts an upgraded 7-zone independent inner spring design to ensure th

£109.66 £139.99
New
Grey - Hybrid Memory Foam Mattress 3ft Single 4ft 4ft6 Double 5ft King 6ft
Available in UK Sizes: 2FT6 - 3FT - 4FT - 4FT6 - 5FT - 6FT. Mattress Type: Ultra Gen Reflex Mattress. Introducing the Ul

£49.99
Twirest

New
Twirest King Mattress, Hybrid Memory Foam and Spring, Zonal Support, Decompression, Medium Firm, Soft and Breathable Clo
Innovative Design: Twirest hybrid spring mattress adopts an upgraded 7-zone independent inner spring design to ensure th

£139.99
18% Off
Hiepunos

New
Hiepunos 5FT King Size Mattress, 10.2 INCH King Memory Foam Sprung Mattress Medium Firm,Comfortable Sleep for Back Pain
3D Breathable fabric: 5FT king size mattress made of high quality breathable 3D knitted fabric, high density sponge for

£122.82 £149.98
New
Pocket Spring Mattress 5000 Pillow Top Double Mattress King Size Mattress
Your new mattress could develop body impressions on the mattress surface after a few nights of you sleeping on the mattr

£335.00
dosleeps

New
dosleeps King Size Mattress 5FT | 10" Memory Foam & Pocket Sprung | 9-Zone Orthopedic Support, Breathable Cover, Motion
★【A GOOD NIGHT SLEEP】With an innovative 9 Zone Support System constructed by individual spring coil pockets. each spring

£197.99
New
MEMORY FOAM MATTRESS ORTHOPAEDIC , 1" 2" 3" 4" 5" Double Size, King size
Designed for superior support and pressure relief, this topper enhances your mattress, providing a more restful night’s

£19.79
eXtreme comfort ltd

New
Extreme Comfort Sleep-Fusion Hybrid 20cms Deep Innerspring & Memory Foam Ultimate Value Mattress, Plush Feel, White, 20c
COIL-SPRUNG HYBRID MEMORY FOAM MATTRESS: 20 cm hybrid design featuring a European-engineered coil spring system combined

£93.65
20% Off
Uliyati

New
Uliyati King Size Mattresses 5FT, 20CM Gel Memory Foam Mattress, Breathable for Cool Sleep & Pressure Relief - Medium, 1
MEMORY FOAM MATTRESS: Uliyati 20CM memory foam mattress features a four-layer foam system, consisting of 1CM comfort mem

£119.99 £149.99
New
MEMORY FOAM MATTRESS ORTHOPAEDIC DOUBLE KING 4FT6 5FT 6FT | 4" 5" 6" 8" 10" 12"
4FT6: Double (W 135cm X L 190cm). 5FT: Kingsize (W 150cm X L 200cm). 6FT: Super Kingsize (W 180cm X L 200cm). Reflex foa

£272.00
19% Off
Zzleoo

New
Zzleoo King Size Mattress - 5FT Memory Foam with Pocket Spring Hybrid, Medium Support, Motion Isolation, Breathable Soft
Ergonomic Hybrid Support & Motion Isolation】This king size mattress features individually wrapped pocket springs that pr

£113.04 £139.99
New
LUXURY ORTHOPAEDIC POCKET 4000 SPRUNG MATTRESS 3FT 4FT6 5FT KING SIZE
Available In UK Sizes: 2FT6 - 3FT - 4FT - 4FT6 - 5FT - 6FT. It is a safe and natural mattress that is supportive, comfor

£158.72
SEZMOONSI

New
SEZMOONSI 5FT King Size Mattress 10.6 Inch, Hybrid Gel Memory Foam, Individually Pocket Sprungs Medium Firm 7 Zone Ortho
7 Zone Orthopedic & Enhanced Edge Support: Our 9.1 Inch deep medium firm king mattress adopts an upgraded 7-zone indepen

£149.99
New
Cool Blue Memory Foam Mattress Sprung 3ft Single 4ft6 Double 5ft King 6ft S King
Available In UK Sizes: 2FT6 - 3FT - 4FT - 4FT6 - 5FT - 6FT. Mattress Colour: 3D Black and White - White Diamond Wave. Ma

£71.16
New
Cool Blue Memory Foam Sprung Mattress 3ft Single 4ft 4ft6 Double 5ft King 6ft
Mattress Type: 8" Pure Foam Sprung Mattress. Mattress Colour: White Cool Wave. Mattress Features. • Mattress depth is 7"

£99.99
New
LUXURY ORTHOPAEDIC POCKET 4000 SPRUNG MATTRESS 3FT 4FT6 DOUBLE 5FT KING SIZE
Available In UK Sizes: 2FT6 - 3FT - 4FT - 4FT6 - 5FT - 6FT. It is a safe and natural mattress that is supportive, comfor

£123.89
New
NEW Memory Foam & Spring Quilted Mattress. 3ft Single, 4ft, 4ft6 Double, 5ft.
4FT6 (Double):approx. 137 x 190cm (4ft6 x 6ft3). 4FT (Small Double) :approx. 122 x 190cm (4ft x 6ft3). 5FT : (King)appro

£89.89
New
Memory Foam Matress Luxury Sprung Mattress 3ft Single 4ft6 Double 5ft King 6ft!!
Available In UK Sizes: 2FT6 - 3FT - 4FT - 4FT6 - 5FT - 6FT. Mattress Type: Micro Quilt Sprung Reflex Foam Mattress. Micr

£109.62
New
MEMORY FOAM MATTRESS ORTHO ULTRA DOUBLE KING 3FT 4FT6 5FT 4" 5" 6" 8" 10" 12"
4FT6: Double (W 135cm X L 190cm). 5FT: Kingsize (W 150cm X L 200cm). 3FT: Single (W 90cm X L 190cm). Reflex foam - This

£82.00
New
LUXURY ORTHOPAEDIC POCKET 4000 SPRUNG MATTRESS 3FT 4FT6 5FT KING SIZE
ORGANIC 4000 POCKET SPRUNG PILLOW TOP MATTRESS 3FT 4FT 4FT6 DOUBLE 5FT KING SIZE. Available In UK Sizes: 2FT6 - 3FT - 4F

£113.36
New
WATERPROOF Spring Mattress Memory Foam 3ft Single 4ft 4ft6 Double 5ft King 6ft
This mattress is designed to cater to various bed types, making it an excellent choice for bunk beds, cabin beds, and id

£59.99
New
5000 Pillow Top Pocket Spring Mattress 4FT 4FT6 Double 5FT King 6FT Super King
Mattress care : Rotate the mattress every 2 weeks for first 3 months and then once every 4 weeks. Do not bend or jump on

£275.00

25 King Size Mattress deals are available from: Amazon, eBay stores, starting from £19.79.
The biggest discount we found is 22% on Twirest King Mattress, Hybrid Memory Foam and Spring, Zonal Support, Decompression, Medium Firm, Soft and Breathable Cloth, Mattress-in-Box, 150x200x22cm at Amazon.
The lowest price we found is £19.79 while the highest is £335.00.
Prices for the best King Size Mattress deals average at £134.25.
Last updated on April 4, 2026.
We scanned these quality online stores and more to deliver you with the best offers online available for King Size Mattress.