Dunno, or Know-Nothing (Russian: Незнайка, Neznayka); from the Russian phrase "не знаю" ("ne znayu"), I don't know) is a character created by Soviet children's writer Nikolay Nosov.

Dunno, recognized by his bright blue hat, canary-yellow trousers, orange shirt, and green tie, is the title character of Nosov's world-famous trilogy, The Adventures of Dunno and his Friends (1954), Dunno in Sun City (1958), and Dunno on the Moon (1966). There have been several movie adaptations of the books.