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Fractal Design Define S Mid Tower Gaming Case

CCL Code: CAS2306
Manufacturer Code: FD-CA-DEF-S-BK
| Manufacturer: Fractal Design

Key Features:

  • PSU not included
  • 0 x 5.25" External Bay(s)
  • 2 x 2.5", 3 x 3.5" HDD Bay(s)
  • Max MB Size: ATX

Delivery Options

Tuesday 26th October via Priority DPD

Free Delivery by Friday 29th October

Collection Options

Tuesday 26th October from Local Collection Point


inc VAT

10 In Stock Now

Buying in bulk or need help? Email our Business Team.


The Fractal Design Define S lends the appearance, sound dampening technology, and support for a wide variety of components from the widely popular Define Series, while introducing a new, innovative internal layout. The Define S case is packed with intelligently designed enthusiast-oriented features delivering a silent case with powerful and expansive air and liquid cooling support, presented in a stunning Scandinavian inspired construction.

The modernized internal layout of the Define S omits the optical drive bays, instead focusing on a clear straight airflow path and uncompromising water cooling support.

The Define S case reaches the highest level of silent computing through strategically placed dense sound-absorbing material, multiple ModuVent™ fan vent covers and finely tuned Dynamic Series fans.

Cooling system

  • Front: 3 – 120/140 mm fans (included is 1 Fractal Design Dynamic GP14 fan, 1000 RPM speed)
  • Rear: 1 – 120/140 mm fan (included is 1 Fractal Design Dynamic GP14 fan, 1000 RPM speed)
  • Top: 3 - 120/140 mm fan (not included) or 1 - 180 mm fan with 165mm hole spacing (not included)
  • Bottom: 1 – 120/140 mm fan (not included)
  • Side: 1 – 120/140 mm fan (not included)
  • Dust filters: Bottom and front intakes

Water cooling compatibility - Radiators

  • Front – 360, 280, 240, 140 and 120 mm radiators of all thicknesses
  • Top – 420, 360, 280, 240, 140 and 120 mm radiators. (A thickness limitation of 55mm for both radiator + fan applies on 420, 280 and 140 mm radiators)
  • Bottom – 120 mm radiator (Use of radiators in the bottom position limits the PSU length to 165 mm)
  • Rear – 120 or 140 mm radiator

Water cooling compatibility - Pumps

  • Pre-drilled holes on the bottom panel, supports many DDC and D5 variants

Water cooling compatibility - Reservoirs

  • Adjustable mounting brackets allow for almost any rectangular mounting screw pattern
  • Maximum distance between the mounting bracket screw positions: 350mm height / 80mm width

Front interface

  • 2 USB 3.0
  • Audio in/out
  • Power button with LED (blue)
  • HDD activity LED (blue)
  • Reset button

Main Features

  • Optimally designed for silent computing, while not compromising on airflow and cooling capabilities
  • Innovative internal layout, providing a perfectly straight airflow path to the CPU heatsink for air cooling set ups or extensive radiator mounting possibilities for water cooling set ups
  • Extensive water cooling support for a case of this size; housing radiators up to 420mm in the top and 360mm in the front
  • Including smart reservoir brackets; featuring drill-free reservoir mounting on the front of the motherboard tray and pre-drilled pump mounting holes on the bottom panel
  • Equipped with ModuVent fan slot covers providing the option of additional cooling or maximum sound absorption
  • Including two Fractal Design Dynamic GP14 140mm fans developed for superlative airflow while still maintaining low noise levels
  • Maintaining a dust-free interior with dust filters that cover the front and bottom air intakes
  • Introducing newly designed hard drive trays placed vertically behind the front partition of the motherboard tray - Three sturdy steel trays with vibration-dampening grommets allowing for installation of one 3.5" or 2.5" drive on each tray, without disrupting the airflow or interfering with the radiator mounting possibilities
  • An additional 2 dedicated steel SSD trays cleanly placed behind the motherboard tray
  • Long motherboard tray extending to the front panel contributing to an extremely clean build, hiding both hard drives and cables
  • Define S model is also available with a large window on the side panel


Number of Bays for Hot Pluggable Hard Drives 3


Expansion Slots 7


USB Ports 2 x USB 3.0
Headphone Ports 1
Microphone In Port 1


Form Factor Computer Case
Case Colour Black
In The Box Define S computer case • User manual • Accessory box
Width 23.3 cm
Depth 52 cm
Height 45.1 cm
Weight 9.1 kg

Key Features

Firewire No
Main Colour Black
Case Type Tower
USB 3.0 Support Yes
Case Form Factor Mid Tower
Power Supply Included No
Optimised for Gaming
80Plus Rated No
PSU Form Factor ATX
Display Model in Showroom No
L.E.D Fan No LED
Internal 3.5" Bay 3
Internal 2.5" Bay 2
Micro-ATX No
Built-in Card Reader No
USB Type-C Support No
Front HDMI No
Side Panel Type Solid
Front Audio Type Separate
Maximum Motherboard Size Supported ATX


Warranty 1 Year

Item Details

Manufacturer Fractal Design
Manufacturer Code FD-CA-DEF-S-BK
EAN 7350041083443
UPC 817301013444
Condition New

Warranty Information

Warranty 1 Year

Manufacturer Information

Manufacturer Fractal Design
Manufacturer Code FD-CA-DEF-S-BK
Questions and Answers

Do you have you a question about the Fractal Design Define S Computer Chassis?

4 / 5 6 reviews


July 2020

Despite decades of technological miniaturisation, ironically this beast of a case is actually bigger and heavier than my first desktop PC bought in the early 1990s. I bought this case not for games but to build a budget media workstation, so don't need all the modern LED nonsense or transparent sides. Chose the Define S because of good reviews and reasonable value. Comes with 2 inbuilt case fans which seem quiet and do the job so far. Note : the fans are 3 pin. Discovered that my mboard fan connectors are 4 pin. They work, just that they don't use the 4th pin (PWM) so cant be controlled so easily as 4pin fans can. Not an issue for me. Overall, happy with it. FOR : Solid construction, good internal layout; plenty of room inside for installation, airflow and extra fans/water cooling; soft rubber around cable holes; thumbscrew easy-access side panels. AGAINST : Massive & heavy; no DVD drive; upward facing front panel ports (will collect dust); no inbuilt SD card reader; wont fit in cupboard of our computer desk :(

Mark Riley

June 2020

Good for airflow and cable management. Good value

Callum Anderson

May 2020

The only negative I have with this case is - no top filter which leaves it looking unfinished there are covers but useless when you have fans in. (research will show you can buy magnetic filters that will fit that is totally worth it) Other than that its the best case and a joy to build computer inside, plenty of room inside its BIG

Gil Melanda

April 2020

Great case, massive airflow, extended radiator support, magnificent cable management.


January 2020

Great kit. Solid, spacious with smart cable and SSD or HDD management. Recommend.


May 2019

For my new PC build I wanted a quiet, minimalist looking PC. None of that RGB nonsense. This case was absolutely perfect for my criteria. Firstly, it looks good, a nice black brushed-aluminium looking front panel mounted onto a solid chassis. It's a large case, but warrants plenty of space to build inside, and the deep side panels grant a lot of space behind the motherboard tray for cable management. Moreover, the case supports mounting for 3 x 2.5/3.5" drives, and 2 x 2.5" drives, also behind the motherboard tray. Meaning that it's very easy to create a very clean looking build to maximize airflow. There's a lot of QoL features built in, such as the sound-dampening foam that lines both side panels and the 3 'Moduvent' slots in the top of the chassis. These can be kept closed, or opened up to install a water-cooling radiator. Below the case is a detachable dust filter for your PSU, and a magnetic dust filter behind the front panel. Included are two fans, and these are pretty quiet and provide decent airflow. I had a few difficulties building inside the case. My motherboard (Aorus Gaming 7 Wifi) had a built-on backplate and this interfered with snapping this into place on the stand-offs so I had to detach it. It was a genuine pleasure to built inside this case, for the price you get an extremely well designed and well made product with plenty of room for all kinds of builds, especially custom loops with pre-drilled mounting holes for reservoirs and so on.