If you owned a bike in the 1980s or before in the UK, it was probably British-made. If you own one today, most likely it’s made abroad.
My 1980s Falcon racing bike was made in England. It is superb quality and a rides like a dream despite its age. Falcon Cycles is still going. The company owns and sometimes uses a number of different former British bicycle brands including Elswick, Hopper, Holdsworth (the Holdsworth brand is also used by Far East manufacturer Planet X Bikes), Falcon (once the second largest bicycle manufacturer in the UK after Raleigh; the factory in Barton-on-Humber closed in the mid-1980s and production was moved to nearby Brigg; in 2006 Falcon ceased UK production entirely, but by this time only a few high end bikes were being assembled in the UK by Falcon and most Falcon bikes were already being made abroad, since about 2002), British Eagle, Coventry Eagle (also previously a motorcycle manufacturer), Townsend, Wearwell and Claud Butler. The same company (Tandem) now owns Dawes cycles (the Dawes factory in Tyseley, Birmingham closed down in around 1990 and production was moved to the Far East) too. Like Raleigh Cycles, Falcon and Dawes (Tandem) do not make bikes in the UK nowadays, all their bicycles now being foreign made.