Ukha (Russian: Уха) is a clear Russian soup, made from various types of fish such as sturgeon, salmon, or cod. It usually contains root vegetables, parsley root, leek, potato, bay leaf, dill, tarragon, and green parsley, and is spiced with black pepper, saffron, nutmeg, and fennel seed. Fish such as perch, tenches, sheatfish, and burbot are sometimes used to add flavour to the soup.

While ukha is a fish dish that is made with broth, calling it a fish soup may not be absolutely correct. "Ukha" started to be used as a term for fish broth in Russian cuisine in the late 17th to early 18th centuries. In earlier times, this term referred to thick meat broths, and then later chicken. Beginning in the 15th century, fish was more and more often used to prepare ukha, thus creating a dish that had a distinctive taste among soups. In XIX century, many travellers visiting Russia claimed that ukha is one of the best dishes in russian quisine.

Vegetables were kept to a minimum when preparing ukha, and in fact, in classic Russian cuisine, ukha was simply a rich fish broth that accompanied fish pies (rasstegai, kuliebiaka, etc.). These days it is more often a fish soup, cooked with potatoes and other vegetables. A wide variety of freshwater fish can be used, and some aficionados opine that one cannot make a good ukha from saltwater fish species. Fresh fish lends the dish the best flavor, and so if frozen fish is used, it is better not to defrost it. Preference is given to smaller, younger fish, with the tail parts of bigger fish discarded.