Fitna (or fitnah, pl. fitan; Arabic: فتنة , فتن: "temptation, trial; sedition, civil strife, conflict") is an Arabic word with extensive connotations of trial, affliction, or distress. Although it is a word with important historical implications, it is also widely used in modern Arabic without the underlying historical connotations.

One might distinguish between the meanings of fitna as used in Classical Arabic and the meanings of fitna as used in Modern Standard Arabic and various colloquial dialects. Due to the conceptual importance of fitna in the Qur'an, its use in that work may need to be considered separately from, though in addition to, the word's general lexical meaning in Classical Arabic.

Aside from its use in the Qur'an, fitna is used as term for the four heavy civil wars within the Islamic Caliphate from the 7th to the 9th century AD.