Particle systems, Subwar 2050, Independence War (I-War) and Independence War 2: Edge of Chaos (Evasive Action needs to be here!).

Ocean Software was also a big publisher before they got gobbled up by Infogrames.
Here on gog I can only think of Tunnel B1, Epic and Inferno (last two by Digital Image Design, TFX, TAW, EF2000 need to be here!).

Then there is Stainless Games which of course is responsible for the Carmageddon games.

And Rage, which made the Incoming games, Antheus: Hostile Waters and Expendable (Darklight Conflict needs to be here!).

Digital Integration, Apache Longbow, Hind, F/A-18 Super Hornet (Tornado needs to be here!).

Gremlin Entertainment, Normality, Slipstream 5000, Realms of the Haunting, Fragile Alligianc (Fatal Racing, Hardwar, Reloaded need to be here!).

Shiny Entertainment, Giants: Citizen Kabuto, Sacrifice, Messiah, MDK, Armed and Dangerous.

Virgin Interactive.

Great to know that you all spending your time to discover studios from the UK, thanks.

Wouldn't use a Git or Google TSV spreadsheet be more handy, perhaps? With the format like Gametitle / Developer / URL where the location is stated. I was attempting to make one for all the developers on the store, not only UK, sadly too monotonous, too tiring, dropped off to prioritize other things for a bit. The bit became years long, still going on.

Why UK, why not GB? Not sure it matters but maybe there are some developers on the Isle of Man or elsewhere not part of the UK but GB.

Uhmm, this post may be seen as political but that was not my intention.

I think it's geography. The Merriam-Webster article mentions the confusing detail.

Quote, "To make things easier on everybody, United Kingdom is also used with the identical meaning [as the term The United Kingdom of Great Britain and Northern Ireland]. To make things even easier, UK is used as an abbreviation of the whole thing." I may be wrong in my reading (due to slight headache caused by coffee), ask a UK person to correct if so, but it seems that to use the UK is appropriate in the context and does include "Great Britain" in itself.

Other way round - 'UK' is the broader term, and includes Northern Ireland as well as Great Britain. The Isle of Man is a self-governing Crown Dependency that isn't part of either GB or the UK. So I guess it's up to the OP to decide whether it counts or not...

As far as I know, they consider themselves Brits.

Sigh! Thanks!

This is how I always understood it, with like a hierarchy of areas being added.

Rowan Software, though they have nothing on gog this needs to change!

Notable games are: Battle of Britain, Flying Corps, MiG Alley, Dawn Patrol, Navy Strike and Overlord.

Blood Omen - Legacy of Kain is a canadian game. But worth to mentioned.
Team17 not so worth to mentioned... khm...

Z: The Game (although only as remake bad back-port from mobile) from already mentioned here Bitmap Bothers.
Hogs of War and Fragile Alliance from Gremlin aka Infrogrames Studio Sheffild.

(UK is more correct term unlike GB, as already explained above, anything else is Commonwealth - include allied to UK countries where same constitutional monarch but independent Parliament (or no more since The Queen death? as i get it be more like tradition and something personal right... Wiki say Charles III still is a monarch for part of Commonwealth))
If Canada is ok listed here
Strategy First
http://www.mobygames.com/browse/games/strategy-first-inc/developed-by/list-games