Koinonia (/ˌkɔɪnoʊˈniːə/)^[1] is a transliterated form of the Greek word κοινωνία, which refers to concepts such as communion or fellowship, joint participation, the share which one has in anything, a gift jointly contributed, a collection, a contribution. It identifies the idealized state of fellowship and unity that should exist within the Christian church, the Body of Christ.

The essential meaning of the koinonia embraces concepts conveyed in the English terms community, communion, joint participation, sharing and intimacy.