The Christadelphians are a restorationist and nontrinitarian Christian denomination. The name means 'brothers and sisters in Christ', from the Greek words for Christ (Christos) and brothers (adelphoi).

Restorationism, also known as Restitutionism or Christian primitivism, is a religious perspective according to which the early beliefs and practices of the followers of Jesus were either lost or adulterated after his death and required a "restoration". It is a view that often "seeks to correct faults or deficiencies by appealing to the primitive church as normative model".