|Place of origin||France, Vichy or United States of America, New York City (disputed)|
|Main ingredients||Leeks, onions, potatoes, cream, chicken stock|
Vichyssoise (// VISH-ees-WAHZ; French pronunciation: [vi.ʃi.swaz]) is a thick soup made of boiled and puréed leeks, onions, potatoes, cream, and chicken stock. It is traditionally served cold but it can be eaten hot. 
The origins of Vichyssoise are a subject of debate among culinary historians; Julia Child called it "an American invention", whereas others observe that "the origin of the soup is questionable in whether it's genuinely French or an American creation".
Louis Diat, a French chef at the Ritz-Carlton in New York City who grew up in Montmarault in the Allier department near the spa resort town of Vichy, is most often credited with its (re)invention. In 1950, Diat told The New Yorker magazine:
In the summer of 1917, when I had been at the Ritz seven years, I reflected upon the potato and leek soup of my childhood which my mother and grandmother used to make. I recalled how during the summer my older brother and I used to cool it off by pouring in cold milk and how delicious it was. I resolved to make something of the sort for the patrons of the Ritz.
The same article explains that the soup was first called Crème Vichyssoise Glacée, after the spa town. In 1930 the restaurant's menu changed from French to English, whereupon it was called Cream Vichyssoise Glacée.
In popular culture
- List of French soups and stews
- List of soups
- List of vegetable dishes
- 1971 Bon Vivant botulism case, which involved tinned vichyssoise soup
- Fox, Eve (24 February 2015). "Warm potato leek soup (vichyssoise)". The Christian Science Monitor. The Christian Science Monitor. Retrieved 2 August 2017.
- Hellman, Geoffrey T. (1950). "Talk of the Town". The New Yorker (12/02). Archived from the original on 14 November 2006.
- Mastering the Art of French Cooking (Hard-cover). Alfred A. Knopf. p. 39. ISBN 0-375-41340-5. Retrieved 2 August 2017.
- Kamp, David. The United States of Arugula, New York: Broadway Books, 2006
- "A Cold, Creamy, Luscious Summer Potato & Leek Soup". The Nibble. The Nibble. 9 September 2012. Retrieved 2 August 2017.