This is a frequently used English idiom. It is primarily used in spoken language and generally only in fairly informal contexts.
This expression is used to tell someone about something which you think they will like. It can relate to anything which a person may enjoy or may be suited to do for example an item of food, a job or a holiday.
The expression “right up your street” is the British English version of the expression whilst in American English the phrase, with the same meaning, is “right up your alley.” In both the British and American version the word “up” is interchangeable with “down” and is used just as often.
There is no definite origin of the expression although the first recorded usage of the metaphorical usage of the American expression dates to 1931. It can be found in M.E. Gilman’s Sob Sister v.65 and reads “it’s about time a good murder broke, and this one is right up your alley.”
The first usage of the British English expression can be traced back earlier than its American equivalent to the year 1929. This can be found in the Publishers’ Weekly magazine and reads “A great many of the books published today are, as the saying is, right up her street.”
An example of the usage of the British English expression can be found in the 1945 novel Brideshead Revisited II which reads “she is a jolly attractive girl, the sort of girl any chap would be glad to have—artistic, too, just down your street.”