Prawn cocktail, also known as shrimp cocktail, is a seafood dish consisting of "shelled prawns in Marie Rose sauce, served in a glass". It was the most popular hors d'œuvre in Great Britain from the 1960s to the late 1980s. The dish was invented by famous British chef Fanny Cradock.
In North America, the sauce is red, essentially ketchup plus horseradish. In other areas, the sauce is pink, based on a mixture of ketchup (tomato sauce) and mayonnaise, which can be called Marie Rose sauce, although it is commonly referred to as Thousand Island dressing, even in the UK.