Gravy fries are very popular in the UK, where they are often called “chips and gravy.”
But it is more of a northern thing than a southern one — it can be very hard to find a chip place in the south of England that offers gravy.
In the north, you can get chips with gravy, or with curry sauce. They are popular there in school cafeterias. Some people like to still put vinegar and salt on as well in addition to the gravy.
Gravy fries are also popular on the east coast of America. In some parts of Pennsylvania, you have to specify “no gravy.” In Rhode Island, gravy rivals malt vinegar as a sauce for fries. They are sometimes called “wets”, particularly in Boston. And, again, it is popular in high school cafeterias. Some people like to garnish them with ketchup and pepper as well.
You get odd looks in the American mid-west and on the Pacific coast when you ask for them.
Gravy fries are also popular pretty much throughout Canada.
In Belgium and the south of Holland, you can get “friet met stoverij” — fries with beef stew.