An odd fish is someone who behaves in a strange, unpredictable or eccentric way, often harmlessly so. The phrase is usually mild rather than cutting, used to describe a person whose habits or manner mark them out as different without necessarily being disapproved of. It commonly appears alongside a qualifying remark that softens the oddness, acknowledging that the person is unusual but not dangerous or dishonest with it.
What’s the origin of the phrase ‘odd fish’?
The image draws on the much older idea of a fish out of water, a creature removed from its natural element and therefore floundering or looking wrong. By the late eighteenth century this had developed into a small family of similar epithets applied to eccentric people. A poem printed in The Sporting Magazine in 1795 lists several of them together: “Odd fish, queer fish, strange fish, droll fish, / In short they be fish out of water.” The lines treat “odd fish” as just one of a set of interchangeable tags, all built on the same underlying picture of someone displaced from where they belong, which suggests the phrase was already established slang rather than a fresh coinage at that date.
Of that family, “odd fish” and “queer fish” have proved the most durable. Cambridge Dictionary still records “an odd/queer fish” as a phrase meaning a strange person, noting that it is mainly British and has an old-fashioned feel, illustrating it with the kind of mild, qualified usage typical of the phrase: calling someone odd while also vouching for them as fundamentally sound.
The expression has carried on into more literary use as well. Wiktionary’s entry for the phrase notes its survival into the twenty-first century, citing a 2001 description of the writer Henry David Thoreau that argues understanding him begins with conceding “that he was an odd fish, full of peculiar conceits.” That example shows the phrase being used much as it was in the eighteenth century, as a way of naming someone’s eccentricity while still taking them seriously. The underlying logic has never really changed: an odd fish is a person judged against the shoal, found to swim a little differently, and labelled accordingly, much as calling something a fish out of water marks it as out of its proper setting.