Russian dressing and Thousand Island have a lot of overlapping ingredients, but there are also some key differences between these iconic slathers.
The ingredient that sets Russian dressing apart is horseradish. Horseradish can be nostril-clearing, but it lends a brighter edge when mellowed by the fat in Russian dressing.
On the other hand, Thousand Island dressing gets an extra sugary pop from sweet pickle relish, and often includes finely chopped hard-boiled egg.
Onion and mustard powder are commonly found in Russian dressing, while a squeeze of mustard or finely chopped onion may be in Thousand Island dressing.
Thousand Island may contain chives, parsley, chopped olives or bell pepper, boiled egg, and can also have a dash of hot sauce. Russian dressing can sometimes include diced pickles.
The names of these two sauces are sometimes used interchangeably. Condiments like a special sauce and comeback sauce are riffs on Russian dressing and Thousand Island.