"Fine kettle of fish" is an idiomatic English expression describing a difficult predicament or a confusing, chaotic state of affairs. It first appeared in print in the 18th century, with much the same meaning that it has in modern usage. Although the exact analogy underlying the expression is unclear, its longevity as a common saying testifies to its enduring popularity. The term has appeared as the title of a 2006 film, a 1998 record, and a large number of fish restaurants.
The earliest recorded use of the expression "a pretty kettle of fish" in this sense occurs in Book 1 of The History of the Adventures of Joseph Andrews, published in 1742, followed by a use in another novel by the same writer, Henry Fielding. In The History of Tom Jones, published in 1749, Fielding uses the expression "a rare kettle of fish." In both cases, the meaning is essentially the modern meaning of the expression: an awkward, difficult predicament. Neither use suggests that the expression is remarkable or unusual in any way, so it may be that these represent the earliest published use of an expression which was already common in everyday British speech. It may also be that Fielding, one of the most popular and influential writers of the 18th century, was responsible for popularizing the use of the saying.
It is unclear exactly why and how "kettle of fish" came to signify a difficult situation. In the 18th century, "kettle" referred to any large pot used to boil water or food; the small pot used to boil water for tea was a "tea-kettle." A mid 18th-century source relates that in northern England, a "kettle of fish" was a type of outdoor meal in which the host cooked salmon in a large cauldron. The term came to refer to the party at which the fish were served as well as to the method of cooking the fish. The idiom may refer to the messy appearance of a cauldron filled with boiling water and disintegrating fish, or to the character and events of these parties themselves.
"Kettle of fish" is one of a number of expressions describing a difficult or confusing situation, many of which bear no obvious relation to the subject. Other examples include "a pretty pickle" and "a fine how d'you do." "A fine mess," popularized by comedy duo Laurel and Hardy, is a more literal representation of the same concept.