The accusative case (abbreviated ACC) of a noun is the grammatical case used to receive the direct object of a transitive verb.

In the English language, the only words that occur in the accusative case are pronouns: "me", "him", "her", "us", "whom", and "them". For example, the pronoun they, as the subject of a clause, is in the nominative case ("They wrote a book"); but if the pronoun is instead the object of the verb, it is in the accusative case and they becomes them ("Fred greeted them"). For compound direct objects, it would be, e.g., "Fred invited her and me to the party".

The accusative case is used in many languages for the objects of (some or all) prepositions. It is usually combined with the nominative case (for example in Latin).

The English term, "accusative", derives from the Latin accusativus, which, in turn, is a translation of the Greek αἰτιατική. The word can also mean "causative", and that might have derived from the Greeks, but the sense of the Roman translation has endured and is used in some other modern languages as the grammatical term for this case, for example in Russian (винительный).

The accusative case is typical of early Indo-European languages and still exists in some of them (including Albanian, Armenian, Latin, Sanskrit, Greek, German, Polish, Romanian, Russian, Serbian, and Ukrainian), in the Finno-Ugric languages (such as Finnish and Hungarian), in all Turkic languages, in Dravidian languages like Malayalam, and in Semitic languages (such as Arabic). Some Balto-Finnic languages, such as Finnish, have two cases for objects, the accusative and the partitive case. In morphosyntactic alignment terms, both do the accusative function, but the accusative object is telic, while the partitive is not.

Modern English almost entirely lacks declension in its nouns; pronouns, however, have an understood case usage, as in them, her, him and whom, which merges the accusative and dative functions, and originates in old Germanic dative forms (see Declension in English).