A fish sandwich is, most generally, any kind of sandwich made with fish. The term is frequently used to describe sandwiches made with breaded, fried fish, which are commonly found in fast food venues.
The earliest example of the fish finger sandwich being created is probably during early 1981 when a nursing assistant, Dean Bevan (then Wilkinson), at the old county psychiatric hospital of St Audry's in Melton, Suffolk found that he regularly had a lot of fish fingers left over following serving the patients breakfast. He discovered that although fish fingers were not particularly popular as a breakfast food, nevertheless, the kitchen served them each morning. So, rather than throw them away he decided to try them as a sandwich snack for his colleagues. Initially they simply consisted of four fish fingers between two slices of white bread along with a little tomato ketchup. They eventually proved popular with nursing staff and it seems quite likely that news of this simple, tasty snack spread by word of mouth and became popular throughout the UK. If anyone has earlier evidence of fish fingers being used in this way then they should include it in this article otherwise it would seem unfair to remove this entry without supporting evidence that can cite fish finger sandwich use prior to 1981.